Update video ACLs when adding to new course

[dennis531]

Is your feature request related to a problem? Please describe.
The course ACLs will not be set when adding a video to a playlist of a new course.

Describe the solution you'd like
Don't display the video for people without write permission in the affected course

Steps:

1. add video to a course playlist. Set the flag e.g. available=false in oc_playlist_seminar_video if video is new in the course
2. update ACLs and start workflow
3. put video into the queue to check for completion of the workflow
4. when retrieving the course videos, the video won't be displayed for people without write permission
   • Only display if the current person in the course has implicit permission to access the video from another course or explicit permission
5. job in the queue was processed successfully
   • Set in the DB that the video in the course playlist is available for all participants (available=true flag)
6. all course participants should now be able to see the video.

Describe alternatives you've considered
Alternatively, we could only show the video to the person adding it until the job in the queue has been successfully processed. This could simplify the query when retrieving the videos and improve the performance.