Annotation management (#1767)

Co-authored-by: jyong <jyong@dify.ai>

api/core/index/base.py

@@ -32,6 +32,10 @@ class BaseIndex(ABC):
     def delete_by_ids(self, ids: list[str]) -> None:
         raise NotImplementedError
 
+    @abstractmethod
+    def delete_by_metadata_field(self, key: str, value: str) -> None:
+        raise NotImplementedError
+
     @abstractmethod
     def delete_by_group_id(self, group_id: str) -> None:
         raise NotImplementedError