improve: introduce isort for linting Python imports (#1983)

api/libs/external_api.py

@@ -1,7 +1,7 @@
 import re
 import sys
 
-from flask import got_request_exception, current_app
+from flask import current_app, got_request_exception
 from flask_restful import Api, http_status_message
 from werkzeug.datastructures import Headers
 from werkzeug.exceptions import HTTPException