Add MauiXamlHotReload to the list of CompilerVisibleProperties (dotnet#34405)

The MauiXamlHotReload MSBuild property was introduced in dotnet#34028 but was
not registered as a compiler-visible property. Without this entry,
Roslyn source generators cannot read the property value via
AnalyzerConfigOptions.GlobalOptions. This change makes it accessible so
IDE and source generators can adjust their behavior based on the
configured hot reload mode (Legacy or SourceGen).

Co-authored-by: Kirill Ovchinnikov <kovchinnikov@microsoft.com>

Author: noiseonwires

src/Controls/src/Build.Tasks/nuget/buildTransitive/netstandard2.0/Microsoft.Maui.Controls.Common.targets

@@ -30,6 +30,7 @@
     <CompilerVisibleProperty Include="MauiXamlLineInfo" />
 		<CompilerVisibleItemMetadata Include="AdditionalFiles" MetadataName="LineInfo" />
     <CompilerVisibleProperty Include="Configuration" />
+    <CompilerVisibleProperty Include="MauiXamlHotReload" />
     <CompilerVisibleProperty Include="EnablePreviewFeatures" />
 	</ItemGroup>
 </Project>