Feat: add meta data filter. (#9405)

### What problem does this PR solve?

#8531 
#7417 
#6761 
#6573
#6477

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

api/db/db_models.py

@@ -744,6 +744,7 @@ class Dialog(DataBaseModel):
         null=False,
         default={"system": "", "prologue": "Hi! I'm your assistant, what can I do for you?", "parameters": [], "empty_response": "Sorry! No relevant content was found in the knowledge base!"},
     )
+    meta_data_filter = JSONField(null=True, default={})
 
     similarity_threshold = FloatField(default=0.2)
     vector_similarity_weight = FloatField(default=0.3)
@@ -1015,4 +1016,8 @@ def migrate_db():
         migrate(migrator.add_column("api_4_conversation", "errors", TextField(null=True, help_text="errors")))
     except Exception:
         pass
+    try:
+        migrate(migrator.add_column("dialog", "meta_data_filter", JSONField(null=True, default={})))
+    except Exception:
+        pass
     logging.disable(logging.NOTSET)