Ability to trigger advancing the step sequencer on note input

[kiwijam]

I'd like to be able to trigger advancing the step sequencer on note input.

An example:

I have a bar with 12 notes.
I have a step sequence like 0001.
I'd like every note to advance the sequence by exactly one step, such that every 4th note lands on a 1 in the sequence, regardless of the note's position in the bar, length of the note or any other factors.

[mkruselj]

This issue will be covered by modmappers (#1384) which will contain this as a mode.

[baconpaul]

although the advance-on-key may be a useful special purpose mode for the step sequencer which would be pretty easy too at least for an SLFO. Definitely a good idea we should build in!

[mkruselj]

Closing this one in favor of modmappers. They really will do this same exact thing.