player control: 'next' button

[PSandro]

Motivation and Context

This change aims to provide a quick way of navigating to the next video in queue. Currently this is possible via the playlist functionality. But opening the playlist view and clicking on the 'next' button there requires some mouse pointer movement an more than 1 click :)

The alternative would be to have a 'skip'/'next' button right next to the pause/play button in the player control bar of the videoplayer. This PR tries to implement exactly that.

fixes #1170

Description

Changes made only affect the web part of gocast. The DataStore and StreamPlaylistEntry is added to the Video.js setup code in TUMLiveVjs.ts. The streamID of the current stream is used to - if exists - fetch the stream's playlist and get the next video in line which then gets linked to via the 'next' button.

Steps for Testing

As I could not test the changes locally myself, testing would rely on the test deployment through CI. One would need to open a stream and confirm that the 'next' button is indeed shown and links to the next video in the playlist. Therefor one could use the existing playlist navigation in the playlist view, then go back and try the same thing using the newly added 'next' button in the player control bar.

Screenshots

Since I could not test the setup locally, there are no screenshots yet. I will updated them as soon as possible.

This is a draft for now since probably more development is needed.

[PSandro]

@alexanderstephan could you please approve the ci workflows? Thanks :)

[alexanderstephan]

@PSandro done :) If you plan to do more work on TUM-Live, we can add you as a project member. Make sure to merge the latest master to get the updated linter settings.