Adding support to provide 3D stereo information from the SEI via FPA (Frame Packing Arrangement)

### [REQUIRED] Use case description
It is great that there is support for reading 3D stereo information (stereoscopic-3d-video-box-st3d), but is it planned to support the SEI FPA (Frame Packing Arrangement) method of extracting this information as well?

### Proposed solution
Adding support to extractors to pull FPA information from the SEI data would be simply wonderful :)

### Alternatives considered
Not applicable

**Links:**
https://www.htcdev.com/devcenter/s3d
https://stackoverflow.com/questions/11747278/how-does-android-mediaplayer-decide-3d-display-by-looking-sei-fpa
https://en.wikipedia.org/wiki/Advanced_Video_Coding (Version 12 (Edition 5): (March 9, 2010))

**Test Media:**
https://rh-testmedia.s3-eu-west-1.amazonaws.com/StereoVideo/Stereo01-1080p-RedBlue.mp4