Fix YouTube playlists continuations

[XiangRongLin]

• I carefully read the contribution guidelines and agree to them.

• Requires sending a POST request instead of GET.

• clientName and clientVersion, which were required as headers previously now need to be part of the request payload.

• continuation id also needs to be part of request body.

• quick and dirty solution (very dirty)

app-debug.zip

I allowed edits by other maintainers, so just adjust it if there are any bugs

[XiangRongLin]

Normally i would say: "just look at the tests and you can see that the fix works"

But as you can see, the tests fail, now figure out thats it's not because of me....

[FireMasterK]

Why are you using the hard-coded key? Iirc there was a method in some class to get the key dynamically 🤔

[XiangRongLin]

Why are you using the hard-coded key? Iirc there was a method in some class to get the key dynamically 🤔

Because it's quick and dirty.
That key was exactly the same in youtube-dl and in the request in my browser, so i didn't bother looking out up more in depth.

Feel free to take this PR as a base and to refine it

[FireMasterK]

I fixed it in FireMasterK@179015b

You can just add this commit :)

[XiangRongLin]

Lovely how i can just open a PR with your changes in your fork against my own branch in my fork. So i don't have to boot up my PC to get the changes 😄

[TobiGr]

Code looks good. I did not have time to take a look at YouTube's requests, but you did, so that should be fine ;)
The tests pass and the changes work in the app.
Can be merged after addressing the review.

[AudricV]

I added the same fix for channels and it also works! See my branch. A debug APK can be downloaded here.

[XiangRongLin]

@TiA4f8R You can open a PR for the channels