youtube-dlc 2020.11.07

Changelog:

[youtube] mix playlist
[youtube] music playlist
[youtube] player/ytinitialData
[youtube] various

[zoom] new extractor
[vlive] extractor updated
[la7] minor url fix
[mailru] minor url fix
[skyitalia]

[core] --all-subs livechat problem excluded from embedding

many more fixes.