Update format for .m3u8 A/V IIIF canvas annotation body.

[mathewjordan]

What does this do?

This update the format property of our IIIF Canvas annotation body for our A/V filesets. If thes annotation.body.type is Sound or Video, then the format will now be application/x-mpegurl. Doing so will help IIIF viewer know better that the resources are HLS streams for .m3u8 playlists.

{
  "id": "https://example.org/whatever.m3u8",
  "type": "Video",
  "format": "application/x-mpegurl",
  "height": 100,
  "width": 100,
  "duration": 360,
}

[mbklein]

👍 Looks good!