Add daemon

[garado]

Non-Python consumers shell out to a fresh light process and parse a json response on every invocation. Even with the in-progress caching work, the per-invocation overhead (interpreter, imports, auth) is still going to make it slow af for them.

This would add support for a persistent process that other apps could talk to instead of spawning light for every command.

• basic grpc setup - just try 'light music list'
• modules
  • music
  • notes
  • contacts
  • podcasts
  • tools
  • settings