Add a VideoPlayer control for desktop apps

Add a built-in VideoPlayer control to desktop projects, with visual designer support, playback controls, seeking, volume, muting and looping. Support local files and bundled project resources, followed by HTTP/HTTPS media in the implementation sequence below. Audio-only media should also work.

Built applications must carry the video runtime they need, without requiring end users to install VLC, codecs or a separate .NET runtime. Applications that do not use video must contain no video runtime payload and must not become materially larger because this control exists.