Create proper integration for HA

[oyvindkinsey]

It is possible to have persistent BLE connections in HA, though the use of a dedicated ESPHome BLE Proxy is recommended.

To make this easier, and to avoid disrupting existing users of this library, the core logic will be refactored into components that the included service can run using MQTT, while the HA integration does so directly.

This will allow automatic discovery of Avi-on based lights in HA and avoids the need for a separate device/vm for running this service.

While this is a fun way for me to learn more python, this will take some time due to also having to learn how to write the HA integration.