mediafoundation: Implement generic URI source
GstMFSourceReader was introduced for an internal of mfvideosrc element to to read data from video capture device.
We can extend the usage of GstMFSourceReader to read data from any URI (http, file or so) if it's supported by MediaFoundation.
Moreover, GstMFSourceReader can be enhanced to be able to read data from UWP file object which would be a more generic
approach than !1001
See also https://docs.microsoft.com/en-us/windows/win32/api/mfreadwrite/nn-mfreadwrite-imfsourcereader