add a way to mute a whole row of sounds in the song grid, and mute individual patterns in the song grid. nf-worh ← Beads

Twinned from https://github.com/cfsh/ninefold/issues/48 by tools/beads/import_github.py's reconcile pass.

on controller, there can be a button / chord for muting a sound, different from deleting it.

on PC we have challenge since right click is for deleting a note, so we need a toggle to switch to muting instead of deleting. I guess we need a row of buttons to switch right-click behaviour.