feat: add shortcuts for insert_query and update_query into Database

example: await db.insert("table_name", base_model)

tests/unit/test_helpers_query.py

@@ -1,6 +1,6 @@
 import pytest
 
-from lnbits.helpers import (
+from lnbits.db import (
     insert_query,
     update_query,
 )