Ported source code for CommunityToolkit.WinUI.Media

[Arlodotexe]

This PR brings over the source code for CommunityToolkit.WinUI.Media for #35.

This includes:

• Support for both UWP and WinAppSDK where possible
• Added nullable type annotations.
• A minor correction to nullable annotations in the Animations package.
• A new internal ArgumentNullExceptionExtensions polyfill (courtesy of @Sergio0694) to enable clean argument validation.

This does not include:

• Any samples, tests or documentation. These will be added in a future PR.
• Backdrop brush functionality on WinAppSDK (unsupported)
• Support for any Uno Platform. The required Win2d and Composition APIs are not available.

[michael-hawker]

Thanks Arlo, were there any other infrastructure or changes made with the sync from @Sergio0694?

[Arlodotexe]

Thanks Arlo, were there any other infrastructure or changes made with the sync from @Sergio0694?

Most of the differences are in WASDK support, e.g. no Backdrop brushes or APIs. Changes all listed above.

[michael-hawker]

@Arlodotexe looks like Win2D doesn't copy on the Any CPU option:

6>C:\Users\.nuget\packages\microsoft.graphics.win2d\1.0.5.1\build\net5.0-windows10.0.17763.0\Microsoft.Graphics.Win2D.targets(24,5): warning : Microsoft.Graphics.Canvas.dll could not be copied because the AnyCPU platform is being used. Please specify a specific platform to copy this file.
6>    1 Warning(s)

[michael-hawker]

Also getting this trying to run after x64 WASDK on the component solution:

[michael-hawker]

Ah, maybe because there's literally no samples/docs?

[michael-hawker]

Looks like new files have issues with CI and need update from main.