The Microsoft Media Foundation (MF) is the successor of DirectShow.
This commit includes two kinds of video capture implementation,
one uses IMFSourceReader interface which is available since Windows Vista
and the other is based on IMFCaptureEngine interface which is available
since Windows 8.
Note that this new video source element cannot be used in UWP app
for now, since device activation using those APIs are not allowed by MS.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/760>
