[WIP] Events, LED

[wmantly]

This is a work in progress to add features for LED and button(s) on the 2mic pi hat. This PR will also include some other house keeping and general quality of life concerns

Completed

• Added pub/sud event bus to allow the code to be decoupled
• Added LED file and events. The LED lights now:
  1. Blink green 3 times when the app service connects to HA
  2. Pulses blue when wake word is activated until VAD end
  3. Pulses yellow while awaiting a response from the server
  4. Pulses green while player response from the server
  5. Is off at all other times

Todo

• Abstract the events_led.py code so it will also work with the 4mic. The code can be abstracted to work with any LED/light via pub/sub.
• Allow a config file to also be used instead of just command line arguments. I personally see this as a QoL issue.
• Write a shell script to set up/start the service.
• Add support for button(s)

I would love comments on this PR, and also some guidance/links to working with the ESPhome package and API.