Feat: Redesign and refactor agent module (#9113)

### What problem does this PR solve?

#9082 #6365

<u> **WARNING: it's not compatible with the older version of `Agent`
module, which means that `Agent` from older versions can not work
anymore.**</u>

### Type of change

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

api/db/db_models.py

@@ -463,6 +463,7 @@ class DataBaseModel(BaseModel):
 
 
 @DB.connection_context()
+@DB.lock("init_database_tables", 60)
 def init_database_tables(alter_fields=[]):
     members = inspect.getmembers(sys.modules[__name__], inspect.isclass)
     table_objs = []
@@ -474,7 +475,7 @@ def init_database_tables(alter_fields=[]):
             if not obj.table_exists():
                 logging.debug(f"start create table {obj.__name__}")
                 try:
-                    obj.create_table()
+                    obj.create_table(safe=True)
                     logging.debug(f"create table success: {obj.__name__}")
                 except Exception as e:
                     logging.exception(e)
@@ -798,6 +799,7 @@ class API4Conversation(DataBaseModel):
     duration = FloatField(default=0, index=True)
     round = IntegerField(default=0, index=True)
     thumb_up = IntegerField(default=0, index=True)
+    errors = TextField(null=True, help_text="errors")
 
     class Meta:
         db_table = "api_4_conversation"
@@ -1009,4 +1011,8 @@ def migrate_db():
         migrate(migrator.add_column("document", "suffix", CharField(max_length=32, null=False, default="", help_text="The real file extension suffix", index=True)))
     except Exception:
         pass
-    logging.disable(logging.NOTSET)
+    try:
+        migrate(migrator.add_column("api_4_conversation", "errors", TextField(null=True, help_text="errors")))
+    except Exception:
+        pass
+    logging.disable(logging.NOTSET)