Add support for numpy images

[naddeoa]

This supports both numpy images and regular nested lists that represent images in the image metric by converting that image data into PIL format and then doing exactly what was happening before.

One thing I need feedback on: is there any loss of information/functionality from logging images in this way? I assume PIL might have modeled some image metadata or manually assigned tags and that wouldn't come through on the np/list log variants of course.

[jamie256]

Let's document the kinds of images this supports, but its a nice start!

[jamie256]

With the change to reference numpy in the image metric, we need to add numpy as a dependency of the whylogs image extra in the pyproject.toml file

the changes are otherwise fine.

[jamie256]

LGTM, thanks!