fix #32161: false collisions with crossstaff notes

When notes are moved cross staff, they were trying to resolve conflicts with notes on the "home" staff, which makes no sense.  So that is fixed.  Unfortunately, there is still no automatic collision avoidance with notes on the "destination" staff. but that would require some re-architecting.  It wasn't done for 1.3 either.

In the vtests below, the middle note in each example really belongs to the bottom staff.