deal dataset metadata and metadata binding (#17544)

api/tasks/clean_dataset_task.py

 from models.dataset import (
     AppDatasetJoin,
     Dataset,
+    DatasetMetadata,
+    DatasetMetadataBinding,
     DatasetProcessRule,
     DatasetQuery,
     Document,
         db.session.query(DatasetProcessRule).filter(DatasetProcessRule.dataset_id == dataset_id).delete()
         db.session.query(DatasetQuery).filter(DatasetQuery.dataset_id == dataset_id).delete()
         db.session.query(AppDatasetJoin).filter(AppDatasetJoin.dataset_id == dataset_id).delete()
-
+        # delete dataset metadata
+        db.session.query(DatasetMetadata).filter(DatasetMetadata.dataset_id == dataset_id).delete()
+        db.session.query(DatasetMetadataBinding).filter(DatasetMetadataBinding.dataset_id == dataset_id).delete()
         # delete files
         if documents:
             for document in documents:

api/tasks/clean_document_task.py

 from core.tools.utils.rag_web_reader import get_image_upload_file_ids
 from extensions.ext_database import db
 from extensions.ext_storage import storage
-from models.dataset import Dataset, DocumentSegment
+from models.dataset import Dataset, DatasetMetadataBinding, DocumentSegment
 from models.model import UploadFile
 
 
                 db.session.delete(file)
                 db.session.commit()
 
+        # delete dataset metadata binding
+        db.session.query(DatasetMetadataBinding).filter(
+            DatasetMetadataBinding.dataset_id == dataset_id,
+            DatasetMetadataBinding.document_id == document_id,
+        ).delete()
+
         end_at = time.perf_counter()
         logging.info(
             click.style(