Trigger app w/ button

As a user, I want to choose which apps will trigger the 'button click'.

Key results:

• App: The user can choose which apps are triggered when the 'button click' command is sent.

• Back-end: The triggering apps must be called, then respond with the result to users via chat and notifications when the command is triggered.

Refs:

• "button click": hold the DevKit2's button to chat with Omi

• Required Firmware 2.0.4+: https://github.com/BasedHardware/omi/releases/tag/omi_firmware_v2.0.4