Upgrade notification

[zoe-codez]

Issue

The page / yaml based nature of the current integration in home assistant means a full restart of the instance is required to pull in updates. There isn't a (currently) obvious indicator if the version of entity yaml is the same as what is written to disk.

Proposed solution

A sensor with a hard coded hash value should be created, which can be used to indicate the current build. This can be compared against a value calculated in the app to provide a Y/N on if a restart is needed. This can be attached to an upgrade/binary_sensor entity to alert that action needs to be taken