Add support for the new channel layout (part 1)

[SamantazFox]

Closes #3371

[unixfox]

Interesting findings: https://www.reddit.com/r/NewPipe/comments/yie0ca/workarounds_for_the_new_youtube_channel_tabs/

[SamantazFox]

Current state of the PR: channel videos are back, but paging is still broken.

[schleussinger]

[46a63e6] works on my instance as described (Channel list is present, paging always returns page 1). Thanks!

[sonicrules1234]

Livestreams (both live and archived) are still missing from the channel pages

[SamantazFox]

[46a63e6] works on my instance as described (Channel list is present, paging always returns page 1). Thanks!

That's quite surprising! This is intended for the "shorts" tab. But glad it's working for you!

Livestreams (both live and archived) are still missing from the channel pages

This will be addressed in the future ^^
For now, I'd like to have at least the channel videos back up.

[SamantazFox]

poke @unixfox: I think we should merge this PR as-is to at least provide the latest videos of a channel.
It's not perfect (continuations are still broken), but would at least help with #3371

[unixfox]

Ever tried to see if the pagination is easier on clients like MWEB or ANDROID?

[SamantazFox]

Ever tried to see if the pagination is easier on clients like MWEB or ANDROID?

Nope, thanks for the idea! (Though I'm pretty sure it won't work on android, given recent exchanges with TiA4f8R over on matrix)