Show possible button shortcuts while editing synth/kit

Toumal

Here's another idea, how about making the pad buttons glow (or breathe) for possible shortcuts while in the synth edit menu and holding shift? This means depending on what part of the menu we are in, and the type (kit/synth/midi/cv), the relevant possible shortcuts could have a faint glow.

I think this should only happen while in an edit menu, otherwise it would collide with the sequencer... i think? Not sure on this one.