[mapping] Implement yaml-configured maps (#8333)

esphome/loader.py

@@ -91,6 +91,10 @@ class ComponentManifest:
     def codeowners(self) -> list[str]:
         return getattr(self.module, "CODEOWNERS", [])
 
+    @property
+    def instance_type(self) -> list[str]:
+        return getattr(self.module, "INSTANCE_TYPE", None)
+
     @property
     def final_validate_schema(self) -> Optional[Callable[[ConfigType], None]]:
         """Components can declare a `FINAL_VALIDATE_SCHEMA` cv.Schema that gets called