Add logging and flash in csrf handler

Author: khteh

src/main.py

@@ -63,6 +63,8 @@ def create_app() -> Quart:
 
     @app.errorhandler(CSRFError)
     async def handle_csrf_error(e):
+        logging.exception(e.description)
+        await flash("Session expired!", "danger")
         if "url" in session and session["url"]:
             return redirect(session["url"]), 400
         else: