We need a proper lexer to be able to understand YouTube's code, which contains /* inside of strings.
For now it's sufficient to just disable comment support altogether.
Fixes#4976, fixes#4979, fixes#4980, fixes#4981, fixes#4982.
Closes#4977.
Initially I was going to use a single method for handling both subtitles and automatic captions, that's why I used the 'list_subtitles' and the 'subtitles' variables.