[release 8] Fix paella player playback bar + introducing Video qualities in player settings

[ferishili]

This PR fixes 2 Issues:

• fixes Video playback bar doesn't hide automatically in some circumstances #387: fix playback bar visibility via paella-core upgrade
• fixes Support for multi-quality videos in the Paella player #383: support multi-quality via new paella plugin

Description

The paella playback bar does not hide automatically when any of the player settings/features is used: #387 (comment)
The paella player does not support multi quality videos: #383 (comment)

Solution

The changes include upgrading paella plugins/core libraries such as paella-core & paella-slide-plugins
as well as introducing new plugin paella-mp4multiquality-plugin with its implementation/addition to the player js!

To TEST

• Patch this PR
• Hard reload the browser you are testing with (since changes are solely on js and we need to remove/refresh the cache)
• Make sure the playback bar gets vanished after opening any player setting while the video is in playing state!
• Make sure to also use a video with different qualities (for example videos created via Studio provide 3 different qualities by default)
• Make sure you can select different qualities via the playback bar settings item "Video Quality"

[snoesberger]

Thanks @ferishili! The multi-quality plugin works, I can now switch between different video qualities and the playbar now hides correctly after the configured amount of time.

From my point of view, this PR is ready to merge.

[dagraf]

@chfsx Since tests from @snoesberger were successfull, can you please review this PR and merge it if everything is fine or comment it, if otherwise? Thx!