Add fault event to balboa (#138623)

* Add fault sensor to balboa

* Use an event instead of sensor for faults

* Don't set fault initially in conftest

* Use event type per fault message code

* Set fault to None in conftest

tests/components/balboa/conftest.py

@@ -68,4 +68,6 @@ def client_fixture() -> Generator[MagicMock]:
         client.pumps = []
         client.temperature_range.state = LowHighRange.LOW
 
+        client.fault = None
+
         yield client