✨ Lyrics file cleanup after kara save

Unfinished and blocked by #1326 (closed), related to #1407 (closed) Could optionally be enabled from advanced settings as long as #1326 (closed) is unsolved.

Cleans up the lyrics file after a kara has been saved, making it more uniform and standarized - causing less git changes when a lyric file is updated

• Remove aegisub garbage section
• Remove aegisub header comments
• Remove unused styles
• Set Title property to kara title (if not set or if default template title)
• Set Original Timing property to kara author(s)
• Unused font detection (?)

Is disabled by default and can be enabled in advanced settings