feat: add possibility to get continuation of YTMusic UpNext Tab

[Duell10111]

The changes add a function to get a continuation of the UpNext PlaylistPanel or PlaylistPanelContinuation.

Therefore a further test was added. :)

[Duell10111]

The test currently seems a bit difficult as the Youtube Music Playlist I used and works from my computer, does not seems to work from the github runner. :/

If someone found a got Playlist alternative, feel free to adapt it. :D

[Duell10111]

@LuanRT Do you see some blockers for this PR? :)

[LuanRT]

@Duell10111 Nope. I'll try it out and merge it as soon as I can.

[LuanRT]

Thanks!