Airtouch4 integration (#43513)

* airtouch 4 climate control integration

* enhance tests for airtouch. Fix linting issues

* Fix tests

* rework tests

* fix latest qa issues

* Clean up

* add already_configured message

* Use common string

* further qa fixes

* simplify airtouch4 domain storage

Co-authored-by: Franck Nijhof <git@frenck.dev>
Co-authored-by: Martin Hjelmare <marhje52@gmail.com>

homeassistant/generated/config_flows.py

@@ -16,6 +16,7 @@ FLOWS = [
     "agent_dvr",
     "airly",
     "airnow",
+    "airtouch4",
     "airvisual",
     "alarmdecoder",
     "almond",