Implement Playback Randomizer

[cosmikwolf]

There should be a Playback Randomizer function which will take incoming notes played, roll a dice and determine if the note should be changed to a random note.

This random note can be created before or after quantization.

The inputs for this should be low note and high note ( note degrees: + or - x notes from the triggered note )

This might have to have two separate functions, one that is before quantization, randomized each beat when the next beat's notes are calculated, and a second function that is randomized at playback time, which is not quantized at all.