refactor(backend): 统一返回的数据格式

pear_admin/orms/_base.py

@@ -11,3 +11,6 @@ class BaseORM(db.Model):
     def delete(self):
         db.session.delete(self)
         db.session.commit()
+
+    def json(self):
+        return {c.name: getattr(self, c.name) for c in self.__table__.columns}