Add config entry for Sonos + Cast (#14955)

* Add config entry for Sonos

* Lint

* Use add_job

* Add Cast config entry

* Lint

* Rename DOMAIN import

* Mock pychromecast in test

homeassistant/config_entries.py

@@ -127,9 +127,11 @@ _LOGGER = logging.getLogger(__name__)
 HANDLERS = Registry()
 # Components that have config flows. In future we will auto-generate this list.
 FLOWS = [
+    'cast',
     'deconz',
     'hue',
     'nest',
+    'sonos',
     'zone',
 ]