MH-13704: Multiple audio tracks support on paella

[miesgre]

Paella supports multiple audio tracks. See: https://paellaplayer.upv.es/demos/multi-audio-tracks/

This PR adds this feature to opencast.

To test this feature you need to:

1. Upload multiple audio tracks to opencast
2. Configure the available languages in paella (see documentation)

This PR contains PR #1054 , so shouldn't be merged before that one!

[lkiesow]

Tried this but got Error! Config file not found. Please configure paella!.
But the configuration file is successfully loaded (HTTP 200).

In the console, I do see this error:

paella_player.js:7569 Uncaught TypeError: Cannot read property 'accessControlClass' of undefined
    at loadAccessControl (paella_player.js:7569)
    at paella_player.js:7597
    at Object.<anonymous> (paella_player.js:15834)
    at c (jquery.min.js:2)
    at Object.fireWith [as rejectWith] (jquery.min.js:2)
    at l (jquery.min.js:2)
    at XMLHttpRequest.<anonymous> (jquery.min.js:2)

[miesgre]

Tried this but got Error! Config file not found. Please configure paella!.
But the configuration file is successfully loaded (HTTP 200).

@lkiesow, I updated the PR, but now this PR contains PR #1054 , so shouldn't be merged before that one!

to test it I downloaded some test files

curl -O https://repository.paellaplayer.upv.es/multi-lang-audio/presenter.mp4
curl -O https://repository.paellaplayer.upv.es/multi-lang-audio/audio-es.m4a
curl -O https://repository.paellaplayer.upv.es/multi-lang-audio/audio-en.m4a

ingested a video using:

curl -f -i --digest -u opencast_system_account:CHANGE_ME -H 'X-Requested-Auth: Digest' \
    http://localhost:8080/ingest/addMediaPackage/import -F creator="`uuidgen`" -F title="Test multiple audio tracks" \
    -F 'flavor=presenter/delivery' -F 'BODY=@presenter.mp4' \
    -F 'flavor=audio_es/delivery' -F 'BODY=@audio-es.m4a' \
    -F 'flavor=audio_en/delivery' -F 'BODY=@audio-en.m4a' 

using the same workflow you used in: #1054 (comment)

and configure paella to use the two audio languages:

"audioTag": {
  "audio_es/delivery": "es",
  "audio_en/delivery": "en"
}