Implement UpdateDataset and UpdateMetadata in GO (#13928)

### What problem does this PR solve?

Implement UpdateDataset and UpdateMetadata in GO

Add cli:
UPDATE CHUNK <chunk_id> OF DATASET <dataset_name> SET <update_fields>
REMOVE TAGS 'tag1', 'tag2' from DATASET 'dataset_name';
SET METADATA OF DOCUMENT <doc_id> TO <meta>


### Type of change

- [ ] Refactoring

api/apps/__init__.py

@@ -136,6 +136,24 @@ def _load_user():
                         return user[0]
         except Exception as e_api_token:
             logging.warning(f"load_user got exception {e_api_token}")
+        # Fallback: try raw authorization value as access_token (for login tokens sent without JWT)
+        try:
+            authorization = request.headers.get("Authorization")
+            if authorization and len(authorization.split()) == 1:
+                # Single value without "Bearer " prefix - try as raw access_token
+                access_token = authorization.strip()
+                if access_token and len(access_token) >= 32:
+                    user = UserService.query(
+                        access_token=access_token, status=StatusEnum.VALID.value
+                    )
+                    if user:
+                        if not user[0].access_token or not user[0].access_token.strip():
+                            logging.warning(f"User {user[0].email} has empty access_token in database")
+                            return None
+                        g.user = user[0]
+                        return user[0]
+        except Exception as e_raw_token:
+            logging.warning(f"load_user raw token fallback got exception {e_raw_token}")
 
 
 current_user = LocalProxy(_load_user)