fixed 'floor music' setting for tracks in custom mode using its own soundtrack selection instead of using the floors soundtrack

fixed antibirth secret room song loop

fixed shop floor in greed mode continuing the fight music after ending a non-boss wave (when used with repentogon)

added extra backup check just in case music queuing is somehow messed with during the run start jingle

added extra checks to a StageAPI workaround function

moved extra custom soundtrack stuff to a separate mod so there won't be conflicts/overwriting from mod updates (and makes it a bit simpler)

fixed AB+ code trying to reference something that only exists in repentance

fixed bug with custom lua soundtracks setting a track to use the run start jingles or main menu music

added the ability to have additional custom soundtrack setups

tweaks to check for stageAPI messing with music in non-custom floors