add ApiReturnModel ー＞return value 統一

backend/app/core/common.py

@@ -0,0 +1,12 @@
+
+from pydantic import BaseModel,Field
+from pydantic.generics import GenericModel
+from typing import Generic,TypeVar,Optional
+
+T = TypeVar('T')
+
+class ApiReturnModel(GenericModel,Generic[T]):
+    code:int = 0
+    msg:str ="OK"
+    data:T
+