Rename the metadata entity field to entity_id

Requires backend!1499, part of backend#861

arkindex_worker/worker/metadata.py

@@ -46,7 +46,7 @@ class MetaDataMixin(object):
                 "type": type.value,
                 "name": name,
                 "value": value,
-                "entity": entity,
+                "entity_id": entity,
                 "worker_version": self.worker_version_id,
             },
         )