Custom Theme Support

[kurokawaerne]

Checklist

• [x] I checked, but didn't find any duplicates (open OR closed) of this issue in the repo.
• [x] I have read the contribution guidelines given at https://github.com/TeamNewPipe/NewPipe/blob/HEAD/.github/CONTRIBUTING.md.
• [x] This issue contains only one feature request. I will open one issue for every feature I want to request.

Describe the feature you want

I think that can be nice with this feature: Custom Theme Support, also this source can help to the development of this feature: https://github.com/jaredrummler/ColorPicker

Is your feature request related to a problem? Please describe it

No, just a suggestion

Additional context

You can check how it's work looking for FlorisBoard project.

How will you/everyone benefit from this feature?

This feature gonna make a interface change, and people gonna use theme editor for make themes and share. ( This help to make a big community because people like customize functions)

[triallax]

This feature request has been decided against previously; see https://github.com/TeamNewPipe/NewPipe/issues/6272#issuecomment-856608962.