add eval metadata placeholders

src/submission/submit.py

@@ -93,6 +93,8 @@ def add_new_solutions(
             "system_type": sys_type,
             "submission_id": submission_id,
             "submission_ts": submission_ts,
+            "evaluation_id": float("nan"),  # This will be set later when the evaluation is launched in the backend
+            "evaluation_start_ts": "",  # This will be set when the evaluation starts
         }
 
     ds = Dataset.from_pandas(submission_df).map(add_info)