Include response to MIDI Bank and Program change messages

[nesdnuma]

I thought it was implicitely included but I didn't succeed in changing a preset with the VST3 version without even trying to choose a bank. Also, I couldn't find a MIDI implementation chart in the user's guide.

[mkruselj]

It's coming in Surge XT 1.3, it's in nightlies now.

#7171

VST3 is... problematic in this regard as long as we use JUCE for our plugin layer.