fix: workflow file add related-id in iteration node (#16255)

Signed-off-by: kenwoodjw <blackxin55+@gmail.com>

api/core/file/enums.py

@@ -49,6 +49,7 @@ class FileAttribute(StrEnum):
     TRANSFER_METHOD = "transfer_method"
     URL = "url"
     EXTENSION = "extension"
+    RELATED_ID = "related_id"
 
 
 class ArrayFileAttribute(StrEnum):

api/core/file/file_manager.py

@@ -34,6 +34,8 @@ def get_attr(*, file: File, attr: FileAttribute):
             return file.remote_url
         case FileAttribute.EXTENSION:
             return file.extension
+        case FileAttribute.RELATED_ID:
+            return file.related_id
 
 
 def to_prompt_message_content(