Add image handling capability in FinalAnswerTool to support saving images as PNG

tools/final_answer.py

@@ -8,6 +8,12 @@ class FinalAnswerTool(Tool):
     output_type = "any"
 
     def forward(self, answer: Any) -> Any:
+        # handle image, e.g. smolagents.agent_types.AgentImage
+        if hasattr(answer, "_raw") and hasattr(answer._raw, "save"):
+            import tempfile
+            with tempfile.NamedTemporaryFile(suffix=".png", delete=False) as f:
+                answer._raw.save(f.name, format="PNG")
+                answer._path = f.name
         return answer
 
     def __init__(self, *args, **kwargs):