Verify support for native embedding .NET MAUI controls within Avalonia applications.

[drasticactions]

For tracking an issue brought up in AvaloniaUI/AvaloniaMauiHybrid#38 (comment)

This should work in our codebase today, but we need to verify and document it (and if it doesn't, then fix it). The goal is to have feature parity with the AvaloniaMauiHybrid codebase and deprecate that repo for .NET 11.