* Breaking change: Rewrite opentherm_gw to add support for more than one OpenTherm Gateway.
Breaks config layout and child entity ids and adds a required parameter to all service calls (gateway_id).
* Add schema and parameter description for service opentherm_gw.reset_gateway.
* Add optional name attribute in config to be used for friendly names.
Fix bugs in binary_sensor and climate platforms.
* pylint fixes
* Remove unused variables.
* Update manifest.json, remove REQUIREMENTS from .py file
* Update CODEOWNERS
* Address issues that were brought up (requested changes):
- Move imports to module level
- Change certain functions from async to sync
- Move constants to const.py (new file)
- Call gateway setup from outside of __init__()
- Move validation of monitored_variables to config schema
* Address requested changes:
- Make module imports relative
- Move more functions from async to sync, decorate with @callback where necessary
- Remove monitored_variables option, add all sensors by default
* Dont use DATA_ROOM_SETPOINT_OVRD in climate.opentherm_gw as it is unreliable with some thermostats.
* Show new target temperature immediately until the backend notices a change
* Only update target temp on the gateway if the value differs from the current target_temperature.
