Add support for ID3 Chapters (CHAP/CTOC)

[AbeEstrada]

This is useful for podcasts with chapters, they have a description of the chapter, and an image.

Specification: https://id3.org/id3v2-chapters-1.0 (broken)

Use this instead https://mutagen-specs.readthedocs.io/en/latest/id3/id3v2-chapters-1.0.html

[mathiascode]

This will require some thought on how to expose the information to users, but parsing should be doable. Could you upload a few sample files?

[AbeEstrada]

@mathiascode all these podcasts use chapters, I'm linking directly to the mp3 files:

• https://traffic.libsyn.com/atpfm/atp576.mp3
• https://www.podtrac.com/pts/redirect.mp3/traffic.libsyn.com/secure/upgrade/upgrade502.mp3
• https://cdn.changelog.com/uploads/friends/33/changelog--friends-33.mp3

And a link to a tool to add chapters: https://overcast.fm/forecast