Add field to track if it was the original task

lm_eval/base.py

@@ -962,6 +962,7 @@ class PromptSourceTask(Task):
             "prompt_name": self.prompt.get_name(),
             "prompt_id": self.prompt.get_id(),
             "prompt_jinja": self.prompt.jinja,
+            "prompt_original_task": self.prompt.metadata.original_task,
         }