Allow homarus to use faststart while converting videos

[bibliophileaxe]

Overview of feature request
The current implementation of ffmpeg conversion does not use faststart, which enables videos to be played instantly. However, faststart does not work on fragmented videos and it also does not work with stdout pipes. In order to do this, we need to remove fragmentation and save the video as a tempfile. The response type would change from StreamedResponse to BinaryFileResponse which will delete the file after sending it.

What kind of user is the feature intended for?
User

What inspired the request?
There is a problem with playing large video files converted with Homarus on chrome. Because the videos are fragmented, chrome requests the moov atom of each fragment before playing these files causing multiple 206 partial content requests. It takes very long (>20 minutes) for large videos to start playing.

References:
https://stackoverflow.com/questions/64661989/chrome-video-tag-cant-play-fragmented-mp4-stream
https://gitlab.com/Shinobi-Systems/Shinobi/-/issues/237
https://gitlab.com/Shinobi-Systems/Shinobi/-/issues/66

What existing behavior do you want changed?
FFMPEG should use faststart instead of fragmentation

Any brand new behavior do you want to add to Islandora?
NA

Any related open or closed issues to this feature request?
NA

[rosiel]

Merged Islandora/Crayfish#162 but there's a need for a version on Crayfish's 3.x branch.