* add sensor platform
* transl. of distance already covered by dev.class
* add untested files to .coveragerc
* add missing state translations
* remove translation key for distance sensor
* proximity entity do not use HA number system
* fix
* extend tests
* make const final to be usable as key for TypedDict
* remove proximity from .coveragerc
* replace typeddict by simple dict definition
* make black happy
* rework to create proximity sensor for each tracked entity and always recalculate all entites
* apply review comments
* move direction of travel calc out of the loop
* make direction of travel an enum sensor
* remove unique_id from sensors
* don't set distance=0 when in monitored zone
* set None when direction is unknown
* keep distance 0 in case arrived for legacy entity
* exclude from nearest when in ignored zone
* keep distance=0 when arrived
* use description name for entity name
* remove uneeded typing
* uses consistent variable name
* fix debug messages
* use entity_id as loop var
* rename device_state to tracked_entity_state
* correct MRO for sensor entity classes
