Sending CMD to JuiceBox

[Snuffy2]

Creating and pinning this Parent issue to reference all the the child issues. Please use this issue for further discussion on sending CMD for now.

See #69 for a PR in progress to send CMDs

Child Issues:

• start/stop mqtt button/switch #39
• Identify unknown fields on messages #52
• Control commands in reply to status telemetry #54

Also see this great GitHub to create a basic library for building and parsing Juicebox UDP messages: https://github.com/philipkocanda/juicebox-protocol