SIENTIAPDE-994

Implement new get_last_timestamp method in Gates class, refactor MLFlow activity methods to return only transformed data, and update PredictionsBatch and PredictionProcess workflows to utilize Activities module. Add detailed docstrings for new methods and enhance test coverage for get_last_timestamp functionality.

laborious/activities/gates.py

@@ -207,3 +207,16 @@ class Gates(BaseActivity):
             'prediction_status': ['Bad'],
             'comment': [input_data['comment']]
         }).to_dict()
+
+    @activity.defn(name="get_last_timestamp")
+    async def get_last_timestamp(self, input_data: dict[str, Any]) -> str:
+        """
+        Gets the last timestamp of the data.
+        Args:
+            input_data (dict): The input data. Contains:
+                data (dict[str, Any]): The data to get the last timestamp from.
+        Returns:
+            str: The last timestamp of the data.
+        """
+        data = DataFrame(input_data['data'])
+        return max(data['timestamp'].values.tolist())