fix #33126: Pedal playback of connected/overlapping pedal segments

The previous implementation was simply adding the Pedal-On and Pedal-Off events at the PedalSegment endpoints. This was problematic, as overlapping pedal segments would cause their Pedal-Off event to occur after the following segment's Pedal-On event. However, we encourage the use of overlapping segments to create a continuous Pedal line.

The solution here is to keep track of the pedal changes within a channel, and correct overlaps when they occur. When a Pedal-On event is added to a channel's list, it checks that the preceding Pedal-Off event occurs at a preceding tick. If it's not, it moves the Pedal-Off event one tick behind the Pedal-On event. This allows a single pedal segment to be active for all the notes it contains, and a series of overlapping pedal segments to stop and start at the overlapping points.

After all the pedal changes are evaluated, the events are added to the main MIDI events list channel by channel.