Map controllers to published input ports in Vuo apps

From user ddelcourt. Split the single feature request into separate requests.

There is a related request on storing and editing published input port values in exported Vuo apps.

This feature request is to provide a menu item in the exported app to map controllers to published input ports.

Team Vuo comment:

Could be like keyboard/midi “learn” mode in Ableton Live, or like setting shortcut keys.