Move EntityCategory to homeassistant.const (#87792)

* Move EntityCategory to homeassistant.const

* Fix more imports

homeassistant/const.py

@@ -1162,3 +1162,19 @@ CAST_APP_ID_HOMEASSISTANT_LOVELACE: Final = "A078F6B0"
 HASSIO_USER_NAME = "Supervisor"
 
 SIGNAL_BOOTSTRAP_INTEGRATIONS = "bootstrap_integrations"
+
+
+class EntityCategory(StrEnum):
+    """Category of an entity.
+
+    An entity with a category will:
+    - Not be exposed to cloud, Alexa, or Google Assistant components
+    - Not be included in indirect service calls to devices or areas
+    """
+
+    # Config: An entity which allows changing the configuration of a device.
+    CONFIG = "config"
+
+    # Diagnostic: An entity exposing some configuration parameter,
+    # or diagnostics of a device.
+    DIAGNOSTIC = "diagnostic"