feat: add support for using teslamate geofences

[brchri]

Allows using Geofences defined in TeslaMate rather than manually specifying a lat/long center point with radii. Some observations regarding this method:

• Geo does not update as frequently as lat/long in MQTT, so there is quite a delay in actually triggering the garage action
  • Presumably this is because the Geofence isn't calculated in realtime with every lat/long update like Tesla-YouQ does, but this is an assumption
• TeslaMate doesn't seem to have any logic for distinction between overlapping geofences. For example, with 2 geofences that have the same center point but different radii, TeslaMate exhibits unpredictable behavior with which geofence gets ascribed to the location
  • This limitation means this method should really only be used for a single geofence, meaning open and close events cannot be defined separately
    • This PR will still support having separate geo's but is at the mercy of the data it receives from TeslaMate; if this is ever fixed, then Tesla-YouQ will already support it, but in the meantime, users should stick to a single geofence
• This method requires defining a DEFAULT_GEOFENCE environment variable for TeslaMate (such as not_home), as some string must be published to the MQTT broker to trigger an event.
  • See this PR in TeslaMate for more info