Add possibility to sequence parameters

[git-moss]

This is asked quite often by users: allow to set different values for a parameter (e.g. Cutoff) for each note in a sequencer. This means to have a simplified (stepped) access to the automation envelopes.

[vokinpirks]

It's called step automation in Ableton Live and parameter lock in some drum machines. Essential feature for sequencing. Even pocket operators can do it.