Embed Cover into Audios

[person12675]

Checklist

• [x] I made sure that there are no existing issues - open or closed - which I could contribute my information to.
• [x] I have read the FAQ and my problem isn't listed.
• [x] 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.
• [x] I have taken the time to fill in all the required details. I understand that the feature request will be dismissed otherwise.
• [x] This issue contains only one feature request.
• [x] I have read and understood the contribution guidelines.

Feature description

The thumbnail of a video downloaded as audio should be embedded as the cover of the audio.

Why do you want this feature?

Some thumbnails are related to the audio and artistically create a unity with the audio.

Additional information

No response