[Bug]: AvaloniaCreatesCommandBinding has different behaviour from CreatesCommandBindingViaCommandParameter

[deryaza]

Describe the bug 🐞

AvaloniaCreatesCommandBinding throws if command is null:

https://github.com/reactiveui/ReactiveUI.Avalonia/blob/main/src/ReactiveUI.Avalonia/AvaloniaCreatesCommandBinding.cs#L76

While default impl does not:

https://github.com/reactiveui/ReactiveUI/blob/main/src/ReactiveUI/Bindings/Command/CreatesCommandBindingViaCommandParameter.cs#L85

Step to reproduce

In view:

this.BindCommand(ViewModel, x => x.LeCommand, x => x.Btn);

And example view model:

using System.Windows.Input;
using ReactiveUI;

namespace ReactiveUIDemo.ViewModels
{
    internal class FooViewModel : ReactiveObject, IRoutableViewModel
    {
        public FooViewModel(IScreen screen) => HostScreen = screen;
        public string UrlPathSegment => "Foo";
        public IScreen HostScreen { get; }
        
        public ICommand? LeCommand { get; }
    }
}

Reproduction repository

https://github.com/reactiveui/ReactiveUI

Expected behavior

ViewModel's null command property should be set in the control

Screenshots 🖼️

No response

IDE

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Operating system

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Version

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Device

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ReactiveUI.Avalonia Version

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Additional information ℹ️

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