Add a Mark-as-watched long-press menu item for playlists

[natebragg]

Checklist

• I made sure that there are no existing issues - open or closed - which I could contribute my information to.
• I have read the FAQ and my problem isn't listed.
• I'm aware that this is a request for NewPipe itself and that requests for adding a new service need to be made at NewPipeExtractor.
• I have taken the time to fill in all the required details. I understand that the feature request will be dismissed otherwise.
• This issue contains only one feature request.
• I have read and understood the contribution guidelines.

Feature description

On a youtube channel's "Playlist" view, if a playlist is selected with a long press a menu should appear (akin to the long press on a single video). On that menu, a "Mark all as watched" item appears that when pushed iterates the list of videos in the playlist and mark all as watched.

Why do you want this feature?

I often have watched long playlists of videos in the official youtube app, and want to also mark them as watched in NewPipe. Right now if I want to mark them all, I have to open the playlist and mark each video manually, which takes forever on playlists with 100+ videos.

Additional information

No response

[opusforlife2]

I don't get the purpose. If you've already watched them all, you can ignore the playlist and move on to newer ones.

[natebragg]

The channel of interest has thousands up on thousands of videos. I don't remember which videos I've seen and which ones I haven't.

[opusforlife2]

Ah, so you basically want to be able to scroll through the channel and view unwatched videos only, but for that you intend to use a bulk marking action by eliminating known watched playlists.

... I don't know, that seems like an overly specific use case to me.

[natebragg]

That's my use case. Perhaps that is overly specific. Hard to know if other people want this. Is it difficult to add? I assumed it would be approximately "copy this code from the long-press video to long-press playlist". Maybe I'm mistaken, I don't know the codebase.