Move buffer pool, converter, and device abstraction layer to public library Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6494>
Adding d3d12compositor element. d3d12compositor will build GPU commands asynchronously and each command is serialized at final render stage. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5875>