move vit functionality into derandomised smoothing toolset

Signed-off-by: GiulioZizzo <giulio.zizzo@yahoo.co.uk>

art/estimators/certification/derandomized_smoothing/vision_transformers/smooth_vit.py

@@ -93,7 +93,7 @@ def __init__(
         if original_shape is not None and output_shape is not None:
             self.upsample = UpSampler(input_size=original_shape[1], final_size=output_shape[1])
 
-    def ablate(self, x: torch.Tensor, column_pos: int) -> torch.Tensor:
+    def ablate(self, x: torch.Tensor, column_pos: Optional[int] = None) -> torch.Tensor:
         """
         Ablates the input colum wise