feat: Add an ffmpeg container

[ReinderVosDeWael]

At present, ffmpeg is run in the API container. This necessitates a far larger than necessary container for the API. This could be made serverless to reduce computational cost.

• Create and host an FFMPEG container
  • Add support for file conversion
  • Add support for file splitting.
• Redirect all FFMPEG usage to this container.

Container availablle at https://github.com/childmindresearch/cmi-ffmpeg-server