Integrate bravagiulia to connect MQTT and TV

[baol]

See https://github.com/baol/bravagiulia

• Get the list of available commands and listen on homely/tv/<TV-NAME>/<command>
• use WOL to power on the TV (homely/tv/<TV-NAME>/On?)
• notify about TV status (On/Off?) as any other device?

The daemon should probably publish the list of supported commands as a retained message (for an example see mosquitto_pub -r option) with qos 1. So that a GUI could just subscribe to the service, get the available buttons, configure the UI, and start controlling the TV.