Add support for importing integrations in the executor (#111336)

* Add support for pre-imports at setup time

alternative solution to #111331

* refactor

* refactor

* refactor

* mark >1.0s integrations

* no point in executor if already loaded

* no point in executor if already loaded

* cleanup

* cleanup

* two more

* one more

* analytics loads a lot more integrations

* cloud

* debug

* psutil, hardwre

* try zha

* Update homeassistant/setup.py

* await

* comments

* coverage

* coverage

* coverage

* move logic to loader

* move logic to loader

* preserve comments

script/hassfest/manifest.py

@@ -265,6 +265,7 @@ INTEGRATION_MANIFEST_SCHEMA = vol.Schema(
         vol.Optional("loggers"): [str],
         vol.Optional("disabled"): str,
         vol.Optional("iot_class"): vol.In(SUPPORTED_IOT_CLASSES),
+        vol.Optional("import_executor"): bool,
         vol.Optional("single_config_entry"): bool,
     }
 )