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/utils/models/minio_dataframe_payload.py

@@ -194,7 +194,7 @@ class MinioDataFramePayload:
             MinioDataFramePayload: Instance with data and/or MinIO fields set.
         """
 
-        if not dataframe or dataframe.empty:
+        if dataframe is None or dataframe.empty:
             return cls(
                 data=None, last_timestamp=now().strftime(DATETIME_FORMAT_WITH_TZ), status=status
             )