SIENTIAPDE-1712

SIENTIAPDE-1712 Add timestamp column to processed data in MLFlow and improve dataframe validation in MinioDataFramePayload

- Added a 'timestamp' column to the processed data in the MLFlow class for better tracking of data entries.
- Updated the validation check in MinioDataFramePayload to handle None values for the dataframe more explicitly.

laborious/activities/mlflow.py

@@ -149,6 +149,8 @@ class MLFlow(MinioManager):
         data.columns.name = None
         data.index.name = None
 
+        data['timestamp'] = data.index
+
         self.debug(f'Processed input data: \n {data.to_csv()}', metadata)
 
         # Request transformation from MLFlow model