Reset all sections

[RobU23]

Implement right-click reset option for each section to, um, reset to defaults...

Ideally, on the section selection buttons, and for each set of sliders (note probability, grid/length probability, accent & probability, legato probability, etc...)

[RobU23]

added reset for:
note probability sliders
seq note size sliders
accent sliders
legato slider
euclid sliders

To Do - full reset of script (scale, oct, root, options for rnd, seq, euc, activelayer)