MUSIC: add a field with a start & stop time for each song, with default being the full song

[RLanger7228 54]

Apple Music used to have a field that allowed you to specify a start time & an end time for each song, if you wanted to specify them.  I found this especially useful for songs from live shows, where there might be applause, crowd noises or talking before or after a song that you might not want to hear when including it in a general playlist.  It wouldn't alter the original dats, but just specify where the playing starts & stops.

[Luke 39785]

Hi, or maybe an a-b repeat feature.