Allow subtitles to be copied to clipboard

[albert-tomanek]

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

Long-pressing (or similar) currently displayed subtitles to copy them to the clipboard. Possibly also copying several 'slides'' worth of subtitles.

Why do you want this feature?

This functionality would be useful for copying passages of spoken lectures into personal notes, or pasting them into LLMs for further discussion.

Additional information

No response