[Enhance] API for purchases, items, operations

- Add API endpoints for purchases, items, and operations
- Header checker? :)

latest version/api/users.py

@@ -1,9 +1,10 @@
+from flask import Blueprint, request
+
+from core.api_user import APIUser
 from core.error import InputError, NoAccess, NoData
 from core.score import Potential, UserScoreList
 from core.sql import Connect, Query, Sql
 from core.user import UserChanger, UserInfo, UserRegister
-from core.api_user import APIUser
-from flask import Blueprint, request
 
 from .api_auth import api_try, request_json_handle, role_required
 from .api_code import error_return, success_return