MBS-5947: use track positions to ensure that if, for ACs, an unchanged track is between two tracks changed to the same thing, it displays as two separate ranges when collapsed
Merge branch 'mbs-5947-ac-collapse-skip' into beta

* mbs-5947-ac-collapse-skip:
  MBS-5947: use track positions to ensure that if, for ACs, an unchanged track is between two tracks changed to the same thing, it displays as two separate ranges when collapsed