Make CommunityToolkit.Maui.UnitTests publicly available as nuget package

[cam14754]

As far as I can tell, this is some of the best unit testing of visual component and hard to unit test stuff. If this was made public, it would enable all to unit test visual components simply by inheriting the base test class. Thoughts?

[stephenquan]

How about creating a new publicly available NuGet package called CommunityToolkit.Maui.Testing.XUnit ?

It would include configurable versions of BaseTest.cs and BaseViewTest.cs refactored from those currently used by CommunityToolkit.Maui.UnitTests.

Toolkit-specific setups such as MediaElement options, Camera and Popup services, and component-specific mocks could remain in CommunityToolkit.Maui.UnitTests project or be provided through optional extensions. The CommunityToolkit's internal tests would consume and extend the new package, validating the package.

The idea is to provide a reusable starting point for anyone writing headless xUnit tests for .NET MAUI components, including custom controls such as the CardView described in Create a ContentView-derived class.