chore: Introductory support for Native AOT builds

Context: unoplatform/uno@559b1f7
Context: unoplatform/uno.toolkit.ui@3ef6d6c
Context: unoplatform/ShowMeTheXAML#30

What do we want? To build and run with Native AOT!
Which in turn requires Uno.Sdk 6.6.0 or later:

	sed -i '' 's/"Uno.Sdk": ".*"/"Uno.Sdk": "6.6.0-dev.15"/g' global.json

	dotnet publish -c Release -r osx-x64 -f net10.0-desktop -p:TargetFrameworkOverride=net10.0-desktop \
	  -bl Uno.Gallery/Uno.Gallery.csproj -p:UseSkiaRendering=true -p:SelfContained=true \
	  -p:PublishAot=true

…which promptly fails to build:

	…Microsoft.NET.Sdk.FrameworkReferenceResolution.targets(120,5): error NETSDK1207:
	  Ahead-of-time compilation is not supported for the target framework.

~~ Build Support for Native AOT ~~

This specifically happens because `Uno.Gallery.csproj` has a
`@(ProjectReference)` to `Uno.Gallery.SourceGenerators.csproj`, which
is a .NET Standard 2.0 project, which doesn't support Native AOT.

To fix this, we need an "indirection": a property which we can set on
the command-line which causes `$(PublishAot)` to be set.

The "conventional" indirection used in unoplatform/uno SamplesApp and
in unoplatform/uno.chefs is `$(SkiaPublishAot)`.  This allows:

	dotnet publish -c Release -r osx-x64 -f net10.0-desktop -p:TargetFrameworkOverride=net10.0-desktop \
	  -bl Uno.Gallery/Uno.Gallery.csproj -p:UseSkiaRendering=true -p:SelfContained=true \
	  -p:SkiaPublishAot=true \
	  -p:EmitCompilerGeneratedFiles=true -p:CompilerGeneratedFilesOutputPath=`pwd`/_gen

which *builds* successfully.  (It doesn't *run* successfully yet;
that's for later.)

~~ Build Support for Android + Native AOT ~~

Remove `$(RunAOTCompilation)` from the Android build, as it's
presence prevents use of Native AOT on Android:

	/usr/local/share/dotnet/packs/Microsoft.Android.Sdk.Darwin/36.1.12/targets/Microsoft.Android.Sdk.Aot.targets(123,5): error
	  Precompiling failed for …/Uno.Gallery/obj/Release/net10.0-android/android-x64/aot-in/System.Collections.dll with exit code 134.
	  Runtime critical type System.RuntimeMethodHandle not found
	# and 24 more similar errors

~~ Build Support for Mobile Side-by-Side Installation ~~

Additionally, to "reasonably easily" support side-by-side execution
of Uno Gallery builds on e.g. iOS or Android, introduce support for
the following MSBuild properties (also done in unoplatform/uno.chefs):

  * `$(ApplicationIdVendorSuffix)`: Value to append to
    `$(ApplicationId)`, so that separate builds have separate names.

  * `$(ApplicationTitleVendorSuffix)`: Value to append to
    `$(ApplicationTitle)`, so that the different builds are
    distinguishable on app launchers.

On iOS, this allows side-by-side installs, but the iOS build doesn't
use the `$(ApplicationTitle)` value.  This is because
`Uno.Gallery/Platforms/iOS/Info.plist` already had a
`CFBundleDisplayName` entry, which overrides `$(ApplicationTitle)`.
Remove the `CFBundleDisplayName` entry so that `$(ApplicationTitle)`
can be used to control `CFBundleDisplayName`.

~~ Desktop Startup Timing ~~

Introduce a trivial "hack" to support app starting time comparisons:
add a `--exit` command-line argument which causes the app to `Exit()`
at the end of `App.OnLaunched()`.  This allows using **time**(1) to
capture "app startup time":

	# CoreCLR:
	% dotnet publish -c Release -r osx-x64 -f net10.0-desktop -p:TargetFrameworkOverride=net10.0-desktop \
	  -bl Uno.Gallery/Uno.Gallery.csproj -p:UseSkiaRendering=true -p:SelfContained=true
	% time Uno.Gallery/bin/Release/net10.0-desktop/osx-x64/publish/Uno.Gallery --exit
	Uno.Gallery/bin/Release/net10.0-desktop/osx-x64/publish/Uno.Gallery --exit  1.08s user 0.32s system 70% cpu 1.982 total

	# Native AOT:
	% dotnet publish -c Release -r osx-x64 -f net10.0-desktop -p:TargetFrameworkOverride=net10.0-desktop \
	  -bl Uno.Gallery/Uno.Gallery.csproj -p:UseSkiaRendering=true -p:SelfContained=true -p:SkiaPublishAot=true
	% time Uno.Gallery/bin/Release/net10.0-desktop/osx-x64/publish/Uno.Gallery --exit
	Uno.Gallery/bin/Release/net10.0-desktop/osx-x64/publish/Uno.Gallery --exit  0.27s user 0.15s system 51% cpu 0.811 total

Or on Windows:

	Measure-Command { .\Uno.Gallery\bin\Release\net10.0-desktop\win-x64\publish\Uno.Gallery.exe --exit | Out-Default } | Select TotalMilliseconds

~~ iOS Startup Timing ~~

No changes are needed; to capture startup time on iOS:

 1. Install the `.ipa` onto your iOS device.

 2. Open **Instruments** (launch Xcode, then
    click Xcode > Open Developer Tool > Instruments)

 3. In Instruments, click File > New ⌘N.

 4. In the **Choose a Template…** window, select **App Launch**.

 5. In the Window which appears, in the central area is a **Target**
    section; from the **Device** dropdown, select your connected iOS
	device, and from the **Target** dropdowns, select **Launch** and
	the Uno Gallery app from the dropdown.

    Note: the Target dropdown shows `CFBundleExecutable` -- which is
	identical regardless of `$(ApplicationIdVendorSuffix)` or
	`$(ApplicationTitleVendorSuffix)` -- so this is	easiest to do if
	there is only *one* Uno.Gallery app installed.

 6. Click File > Record Trace ⌘R to start recording, which will launch
	the app on the device.

 7. When the app has finished launching, force-quit the app.
    Instruments will now start processing the data.

 8. Type ⌘4 to switch to **App Lifecycle**.  This shows a table of
    events with Start, Duration, and Narrative columns.
    Look for the *Launching - Initial Frame Rendering* Narrative entry.
    The Start value is the time taken to launch the app.

    |         Start |  Duration | Narrative                                         |
    | ------------: | --------: | :------------------------------------------------ |
    | 00:00.000.000 | 480.77 ms | The system took 480.77 ms to create the process.  |
    |             … |         … | …                                                 |
    | 00:01.306.446 |   4.41 ms | Launching – Initial Frame Rendering               |

    In this run, app startup time was 1.306 seconds.

~~ Native AOT Runtime Fixes ~~

Begin fixing some of the runtime issues with Native AOT builds.
The following messages would appear on the Console during startup:

	fail: Uno.Gallery.Sample[0]
	      Failed to initialize data for `AutoSuggestBoxSamplePage`. dataType: Uno.Gallery.Views.Samples.AutoSuggestBoxSamplePageViewModel. Exception: System.MissingMethodException: No parameterless constructor defined for type 'Uno.Gallery.Views.Samples.AutoSuggestBoxSamplePageViewModel'.
	         at System.ActivatorImplementation.CreateInstance(Type, Boolean) + 0x180
	         at Uno.Gallery.Sample.CreateData(Type) + 0x3a
	fail: Uno.Gallery.Sample[0]
	      Failed to initialize data for `BarometerSamplePage`. dataType: BarometerSamplePageViewModel. Exception: System.MissingMethodException: No parameterless constructor defined for type 'BarometerSamplePageViewModel'.
	         at System.ActivatorImplementation.CreateInstance(Type, Boolean) + 0x180
	         at Uno.Gallery.Sample.CreateData(Type) + 0x3a

Plus 19 more similar messages.

These `fail` messages appear because of missing "reflection metadata"
(unoplatform/uno@559b1f78), and we can fix these by using the
`[DynamicallyAccessedMembers]` and `[DynamicDependency]` attributes.

In order to use `[DynamicallyAccessedMembers]`, we need either a
generic type parameter or a `typeof()` expression.  Searching around,
there are useful places `typeof()` is already used; from
`Uno.Gallery.SourceGenerators` generated output, in
`$(CompilerGeneratedFilesOutputPath)`, we have:

	// …/App.Samples.g.cs
	public partial class App {
	  public static Sample[] GetSamples()
	  {
	    return new[] {
	      // …
	      new global::Uno.Gallery.Sample(new global::Uno.Gallery.SamplePageAttribute(category: (global::Uno.Gallery.SampleCategory)(2), title: "AutoSuggestBox", source: (global::Uno.Gallery.SourceSdk)(0), glyph: "") { Description = @"Represents a text control that makes suggestions to users as they enter text.", DocumentationLink = "https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.controls.autosuggestbox?view=windows-app-sdk-1.3", DataType = typeof(global::Uno.Gallery.Views.Samples.AutoSuggestBoxSamplePageViewModel), SortOrder = 2147483647 }, typeof(Uno.Gallery.Views.Samples.AutoSuggestBoxSamplePage)),
	      // …
	    };
	  }
	}

Which has the handy benefit of containing *both*
`AutoSuggestBoxSamplePage` and `AutoSuggestBoxSamplePageViewModel`,
which were mentioned in the `fail` message.

This in turn makes the fix straightforward: update the `Sample` and
`SamplePageAttribute` types to use `[DynamicallyAccessedMembers]` on
their respective `Type` parameters and properties to preserve
constructors (from the original message) and properties, which almost
certainly will be needed anyway.
(Property preservation is reflexive at this point.)

If you select **UI components > AutoSuggestBox** in the left-side
tree view, then click the `<>` "Show XAML" button, nothing is shown
*and* the following messages are written to the Console:

	fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
	      The [ShowMeTheXAML:XamlDisplayExtensions.Header] property getter does not exist on type [ShowMeTheXAML.XamlDisplay]
	fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
	      The [ShowMeTheXAML:XamlDisplayExtensions.Description] property getter does not exist on type [ShowMeTheXAML.XamlDisplay]
	fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
	      The [ShowMeTheXAML:XamlDisplayExtensions.Options] property getter does not exist on type [ShowMeTheXAML.XamlDisplay]
	fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
	      The [ShowMeTheXAML:XamlDisplayExtensions.PrettyXaml] property getter does not exist on type [ShowMeTheXAML.XamlDisplay]
	fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
	      The [ShowMeTheXAML:XamlDisplayExtensions.ShowXaml] property getter does not exist on type [ShowMeTheXAML.XamlDisplay]

This is because WPF Attached Properties require use of
`[DynamicDependency]` to ensure that the required methods are
accessible via Reflection; see also unoplatform/uno.toolkit.ui@3ef6d6ce.
Update all use of `DependencyProperty.RegisterAttached()` so that
required methods are retained.

Unfortunately, while this fixes the above `fail` messages, clicking
the `<>` "Show XAML" button still does nothing.

Fixing the `<>` "Show XAML" button requires
unoplatform/ShowMeTheXAML#30 and replacing the existing
`XamlDisplay.Init()` invocation with `XamlDictionary.Init()`.
Bump to Uno.ShowMeTheXAML 2.0.0-dev0026 to get this fix, and bump
`Uno.Sdk` within `global.json` to `6.4.58` so that things still build.

If you select **UI components > BreadcrumbBar** in the left-side
tree view, then the **BreadcrumbBar with Custom DataTemplate**
section on the right-hand page doesn't show anything, and Console
output contains:

	fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
	      The [Name] property getter does not exist on type [Uno.Gallery.Entities.Data.Folder]
	fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
	      The [ItemCount] property getter does not exist on type [Uno.Gallery.Entities.Data.Folder]
	fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
	      The [Description] property getter does not exist on type [Uno.Gallery.Entities.Data.Folder]

Fix this by adding `[Microsoft.UI.Xaml.Data.Bindable]` to
`Uno.Gallery.Entities.Data.Folder`.  The use of `[Bindable]` causes
the `Uno.UI.SourceGenerators.BindableTypeProvider` source generator
to emit `BindableType(…, typeof(Folder))` to `BindableMetadata.g.cs`,
which cause all public properties to be added to reflection metadata.

Add `[Bindable]` to all other types containing properties within
`Uno.Gallery.Entities.Data`.  This fixes a number of other samples
and messages such as:

	fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
	      The [Color] property getter does not exist on type [Uno.Gallery.Entities.Data.Record]

If you select **UI features > Binding** in the left-side
tree view, the right-hand panel would be subtly different between
CoreCLR and Native AOT:

  * CoreCLR: `The length is: [empty]`
  * Native AOT: `The length is:`

Worse, if you enter text into "myTextBox", the bound fields properly
update under CoreCLR.  For example, enter "123" into "myTextBox",
and CoreCLR would show:

> The text of myTextBox is: 123
> The length is: 3

Under Native AOT, *nothing* updates.

Console output contains:

	fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
	      The [Text] property getter does not exist on type [Uno.Gallery.Views.Samples.BindingSamplePageViewModel]
	fail: Uno.UI.DataBinding.BindingPropertyHelper[0]
	      The [TextLength] property getter does not exist on type [Uno.Gallery.Views.Samples.BindingSamplePageViewModel]

Fix this by adding `[Bindable]` to `BindingSamplePageViewModel`.
(Which means "just add `[Bindable]`!" is quickly becoming my favorite
answer to everything.  Unless the type has `required` or `init`-only
properties; see also unoplatform/uno.chefs@06f4f804.)

Continue this pattern: update all types which implement
`INotifyPropertyChanged` or inherit from a type which implements
`INotifyPropertyChanged` to have `[Bindable]`.  This fixes the
following `fail` messages, among others:

	The [AccelerationX] property getter does not exist on type [Uno.Gallery.Views.Samples.AccelerometerSamplePageViewModel]
	The [AccelerationY] property getter does not exist on type [Uno.Gallery.Views.Samples.AccelerometerSamplePageViewModel]
	The [AccelerationZ] property getter does not exist on type [Uno.Gallery.Views.Samples.AccelerometerSamplePageViewModel]
	The [AccelerometerAvailable] property getter does not exist on type [Uno.Gallery.Views.Samples.AccelerometerSamplePageViewModel]
	The [ButtonContent] property getter does not exist on type [Uno.Gallery.Views.Samples.AccelerometerSamplePageViewModel]
	The [ButtonContent] property getter does not exist on type [Uno.Gallery.Views.Samples.GeolocatorSamplePageViewModel]
	The [GeolocatedAccuracy] property getter does not exist on type [Uno.Gallery.Views.Samples.GeolocatorSamplePageViewModel]
	The [GeolocatedAltitude] property getter does not exist on type [Uno.Gallery.Views.Samples.GeolocatorSamplePageViewModel]
	The [GeolocatedLatitude] property getter does not exist on type [Uno.Gallery.Views.Samples.GeolocatorSamplePageViewModel]
	The [GeolocatedLongitude] property getter does not exist on type [Uno.Gallery.Views.Samples.GeolocatorSamplePageViewModel]
	The [GeolocatedTimestamp] property getter does not exist on type [Uno.Gallery.Views.Samples.GeolocatorSamplePageViewModel]
	The [LastReadTimestamp] property getter does not exist on type [Uno.Gallery.Views.Samples.AccelerometerSamplePageViewModel]
	The [LastShakeTimestamp] property getter does not exist on type [Uno.Gallery.Views.Samples.AccelerometerSamplePageViewModel]
	The [ListenButtonContent] property getter does not exist on type [Uno.Gallery.Views.Samples.ClipboardSamplePageViewModel]
	The [Message] property getter does not exist on type [Uno.Gallery.Views.Samples.ClipboardSamplePageViewModel]
	The [ReportInterval] property getter does not exist on type [Uno.Gallery.Views.Samples.AccelerometerSamplePageViewModel]
	The [ShakeCount] property getter does not exist on type [Uno.Gallery.Views.Samples.AccelerometerSamplePageViewModel]
	The [ToggleButtonContent] property getter does not exist on type [Uno.Gallery.Views.Samples.GeolocatorSamplePageViewModel]

Author: jonpryor

Directory.Packages.props

@@ -15,8 +15,8 @@
 		<PackageVersion Include="Uno.UITest.Helpers" Version="1.1.0-dev.70" />
 		<PackageVersion Include="Xamarin.UITest" Version="4.4.1" />
 
-		<PackageVersion Include="Uno.ShowMeTheXAML" Version="2.0.0-dev0015" />
-		<PackageVersion Include="Uno.ShowMeTheXAML.MSBuild" Version="2.0.0-dev0015" />
+		<PackageVersion Include="Uno.ShowMeTheXAML" Version="2.0.0-dev0026" />
+		<PackageVersion Include="Uno.ShowMeTheXAML.MSBuild" Version="2.0.0-dev0026" />
 
 		<PackageVersion Include="Uno.CommunityToolkit.WinUI.UI.Controls" Version="7.1.200" />
 		<PackageVersion Include="Uno.CommunityToolkit.WinUI.UI.Controls.DataGrid" Version="7.1.200" />

Uno.Gallery/App.xaml.cs

@@ -71,6 +71,11 @@ protected override void OnLaunched(LaunchActivatedEventArgs e)
 
 			this.Log().Debug("Launched app.");
 			OnLaunchedOrActivated();
+
+			if (e.Arguments?.Contains("--exit") ?? false)
+			{
+				Exit();
+			}
 		}
 
 		private void OnLaunchedOrActivated()
@@ -486,7 +491,7 @@ internal static void InitializeLogging()
 
 		private void ConfigureXamlDisplay()
 		{
-			XamlDisplay.Init(GetType().Assembly);
+			XamlDictionary.Init();
 		}
 
 		private void ConfigureFeatureFlags()

Uno.Gallery/Entities/Data/DividerItem.cs

@@ -5,6 +5,7 @@
 
 namespace Uno.Gallery.Entities.Data
 {
+	[Microsoft.UI.Xaml.Data.Bindable]
 	public class DividerItem
 	{
 		public DividerItem(int i)

Uno.Gallery/Entities/Data/Folder.cs

@@ -3,6 +3,7 @@
 
 namespace Uno.Gallery.Entities.Data
 {
+	[Microsoft.UI.Xaml.Data.Bindable]
 	public class Folder
 	{
 		public Folder(string name, int itemCount, string description)

Uno.Gallery/Entities/Data/Plant.cs

@@ -5,6 +5,7 @@
 
 namespace Uno.Gallery.Entities.Data;
 
+[Microsoft.UI.Xaml.Data.Bindable]
 public class Plant : IComparable
 {
 	public Plant(

Uno.Gallery/Entities/Data/Record.cs

@@ -4,6 +4,7 @@
 
 namespace Uno.Gallery.Entities.Data
 {
+	[Microsoft.UI.Xaml.Data.Bindable]
 	public class Record
 	{
 		public Record(string compositionName, string artistName, string color)

Uno.Gallery/Entities/Data/TestCollections.cs

@@ -42,6 +42,7 @@ public void ResetChipItems()
 			}
 		}
 
+		[Microsoft.UI.Xaml.Data.Bindable]
 		public class SelectableData : InpcObject
 		{
 			public int Index { get => GetProperty<int>(); set => SetProperty(value); }
@@ -51,6 +52,7 @@ public class SelectableData : InpcObject
 			public override string ToString() => $"Item #{Index}";
 		}
 
+		[Microsoft.UI.Xaml.Data.Bindable]
 		public class InpcObject : INotifyPropertyChanged
 		{
 			public event PropertyChangedEventHandler PropertyChanged;

Uno.Gallery/Entities/Data/TreeItem.cs

@@ -3,6 +3,7 @@
 
 namespace Uno.Gallery.Entities.Data
 {
+	[Microsoft.UI.Xaml.Data.Bindable]
 	public class TreeItem
 	{
 		public TreeItem(string name)

Uno.Gallery/Entities/Sample.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
@@ -13,7 +14,11 @@ namespace Uno.Gallery
 	[Bindable]
 	public class Sample
 	{
-		public Sample(SamplePageAttribute attribute, Type viewType)
+		internal const DynamicallyAccessedMemberTypes ViewRequirements =
+			  DynamicallyAccessedMemberTypes.PublicConstructors
+			| DynamicallyAccessedMemberTypes.PublicProperties;
+
+		public Sample(SamplePageAttribute attribute, [DynamicallyAccessedMembers(ViewRequirements)] Type viewType)
 		{
 			Category = attribute.Category;
 			Title = attribute.Title;

Uno.Gallery/Entities/SamplePageAttribute.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.ComponentModel;
 using System.Linq;
 using System.Text;
@@ -30,6 +31,7 @@ public SamplePageAttribute(SampleCategory category, string title, SourceSdk sour
 
 		public string DocumentationLink { get; set; }
 
+		[DynamicallyAccessedMembers(Sample.ViewRequirements)]
 		public Type DataType { get; set; }
 
 		public SourceSdk Source { get; }