Add min max transforms to visualize_transforms

[marinabar]

What this does

Allows to visualize maximum and minimum transformations that could be applied to your dataset given a specified min_max range. Saves two additional files min.png and max.png for each transform.

How it was tested

Test on various configs, including config files like

python lerobot/scripts/visualize_image_transforms.py --config-path=/my/config/path/default.yaml

How to checkout & try? (for the reviewer)

You can run the same on any config parameters. For example

python lerobot/scripts/visualize_image_transforms.py training.image_transforms.contrast=(0.5, 0.5)

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