Add support for P010/P012/P016 formats

They are the 10/12/16bit equivalents of NV12 and at least P010 is widely supported for a while now, so let's support them.

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How to test:

• have a GPU that supports P010 with VA-API, such as recent AMD generations
• have a 10bit encoded file, such as "Camp by Sony" from https://kodi.wiki/view/Samples
• build gst with gstreamer/gstreamer!5275 (merged)
• enter build env (./gst-env.py in the gstreamer root folder)
• gst-launch-1.0 filesrc location=~/Videos/Camp_by_Sony.mp4 ! qtdemux ! h265parse ! vah265dec ! vapostproc ! waylandsink fullscreen=1
• mpv --hwdec=vaapi --vo=dmabuf-wayland ~/Videos/Camp_by_Sony.mp4 --fs works as well (needs mpv from git)

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See also

• https://learn.microsoft.com/en-us/windows/win32/medfound/10-bit-and-16-bit-yuv-video-formats
• gstreamer/gstreamer!5275 (merged)
• https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3244