Adds the GPU views for WinUI, but there are a few othe things it need
to do:
- Builds ANGLE as this is the primary interop between SkiaSharp and
DirectX
- Builds an interop library that extends types needed for interacting
with ANGLE
- Enables AngleSwapChainPanel as this is the WinUI view that sets up
the GL context
- Enables the SKSwapChainPanel as this is the SkiaSharp accelerated
view
- Add a new NativeAssets package for WinUI native files
