add json field to store any additional blob of data that may be missing; also populate db when dumping listings

crawler/alembic/env.py

@@ -6,6 +6,7 @@ from sqlalchemy import pool
 from alembic import context
 from models import Listing  # Import all models here
 from database import engine
+import sqlmodel
 from sqlmodel import SQLModel
 
 # this is the Alembic Config object, which provides