Assume batch-dimension in window for occlusion

[chr5tphr]

• when supplying an int in attribution.Occlusion, the window size and strides where expanded over all dimensions, including the first, which is most of the time the batch dimension, and would lead the sliding window to also move over the batch dimension
• the first dimension is now assumed to be the batch dimension, and when supplying an int for the window and stride sizes, the window size will be set to the full input in the batch dimension