Lazy loading of service descriptions (#11479)

* Lazy loading of service descriptions

* Fix tests

* Load YAML in executor

* Return a copy of available services to allow mutations

* Remove lint

* Add zha/services.yaml

* Only cache descriptions for known services

* Remove lint

* Remove description loading during service registration

* Remove description parameter from async_register

* Test async_get_all_descriptions

* Remove lint

* Fix typos from multi-edit

* Remove unused arguments

* Remove unused import os

* Remove unused import os, part 2

* Remove unneeded coroutine decorator

* Only use executor for loading files

* Cleanups suggested in review

* Increase test coverage

* Fix races in existing tests

tests/components/device_tracker/test_init.py

@@ -345,6 +345,7 @@ class TestComponentsDeviceTracker(unittest.TestCase):
                         CONF_PLATFORM: 'test',
                         device_tracker.CONF_CONSIDER_HOME: 59,
                     }})
+                self.hass.block_till_done()
 
         self.assertEqual(STATE_HOME,
                          self.hass.states.get('device_tracker.dev1').state)
@@ -586,6 +587,7 @@ class TestComponentsDeviceTracker(unittest.TestCase):
                         CONF_PLATFORM: 'test',
                         device_tracker.CONF_CONSIDER_HOME: 59,
                     }})
+                self.hass.block_till_done()
 
         state = self.hass.states.get('device_tracker.dev1')
         attrs = state.attributes