libobs: Fix FFmpeg constants

(This commit also modifies the deps/media-playback, obs-ffmpeg, and
win-dshow modules)

More fixes due to ffmpeg renaming some constants and deprecating
AVFMT_RAWPICTURE and AV_PIX_FMT_VDA_VLD.
Latter replaced by AV_PIX_FMT_VIDEOTOOLBOX per ffmpeg dev advice.

Closes jp9000/obs-studio#1061