Add search in playlist for saved playlists

[yuval-herman]

• [✅] I carefully read the contribution guidelines and agree to them.
• [✅] I checked if the issue/feature exists in the latest version.

I use newPipe primarily to listen to music which is why I usually only use it as a media player.

I have playlists with hundreds of songs in them and I thought it would be awesome and pretty trivial to add a search in playlist button or something so that you could find your songs and start the playlist from there easily.

[selurvedu]

+1
Searching for saved playlist names and subscriptions would be nice to have as well.

[vomindoraan]

I would benefit greatly from this feature. Please implement it!

[gcoimbra]

I would benefit greatly from this feature. Please implement it!

I would like to remember you that NewPipe is free software maintained by voluntaries.

I advise you to consider donating so developers can spend more time on it:
https://liberapay.com/TeamNewPipe

[vomindoraan]

@gcoimbra Would it be possible to assign a cash bounty to this specific issue? If so, please let me know how.

[opusforlife2]

@vomindoraan Answered in #6544.