Add the option to log images

[adamltyson]

Is your feature request related to a problem? Please describe.
It would be useful (e.g. in image processing pipelines) to have an easy way to save images, e.g. intermediate processing steps for debugging.

Describe the solution you'd like
It should be easy to do something like:

from fancylog import log_image
log_image(numpy_array, name="median_filtered")

This should be saved into a sensible place, e.g. logging_directory/fancylog/images, probably as a tiff by default. The path should be saved into the main log.

Original description by @IgorTatarnikov: #56 (comment)