Support remapping of poly aftertouch events (on pattern tracks)

[YPares]

Re-mapping poly aftertouch events should be just as simple as remapping the note offs (after all those two MIDI messages differ by only 1 bit), however on my aftertouch branch this is not working correctly (at least in Bitwig). Aftertouch events are transmitted only when they are mapped to a note that actually was received by Arpligner. So if you are hitting C3 (in a pattern) and sending aftertouch events on that note, these aftertouch events will be mapped and transmitted only if the current chord does contain a C3.

JUCE code does not seem fishy, so maybe that's a Bitwig problem. I'll check with another DAW.