Joystick button should call action only once

[rafaellehmkuhl]

Calling several times during the button press can cause several problems, like APIs being spammed with several HTTP calls, or JavaScript code being run multiple times.

[ES-Alexander]

#1475 is potentially relevant here. It definitely seems worthwhile to only trigger on edge events (e.g. press/release, rather than repeatedly during hold), because then actions that want to trigger repeatedly during hold can do so themselves, whereas more standard actions can just be called once per button press.