Extract more-complex chapters from the pinned comment; select "normal" chapters or comment chapters

[Lazyt3ch]

Hi Ilya,

I've found a case where each comment line can contain either one or more chapters, or no chapters at all: https://www.youtube.com/watch?v=PzlLXQ3RaDs
I've added some code to extract chapters from such comments.

I've also found a case where the chapters provided in the pinned comment are much better than the "key moments" automatically added by YouTube: https://www.youtube.com/watch?v=5Gt61EX6HZ4
In that case, when the extension tries to fetch chapters, it gets the "key moments" instead – and displays them as chapters. Unfortunately, the result makes no sense.
I've made minor changes to the extension, and now, if both the "normal" chapters (that is, either full-fledged chapters or "key moments") and the chapters extracted from the pinned comment are available, it select the more-numerous ones.

Actually, both cases are pretty unusual, so I'm not sure if handling them is worth the effort.

Regards,
Rashid

P.S. I've also added the following functionality:

• Handling abnormal comment chapters (titles before timestamps)
• Sorting chapters by timestamps