add endpoint to upload announcements

[adarshm11]

sce tv would be perfect to upload announcements (flyers, videos, etc) so people who enter the sce room can see what's going on.

game plan

• we need to create an endpoint that can accept an image or video from the one.sce/ sce tv UI
  • probably requires a new page on there that accepts image/video uploads
• if it's a video, we should turn it into an mp4 and queue it up as the new interlude video for the tv
• if it's an image, we need to find a way to turn it into a 15 second mp4 video, then queue it up as the interlude video