Implement histogram equalization for astronometric calibration

[juanep97]

Implement histogram equalization during astrometric calibration, it might lead to a general speed up of the process; specially for images with sources of very different brightness (such us those containing bright stars). Those kind of images currently take a longer time to calibrate, or even fail; histogram equalization might allow their calibration. Some tests will be needed to decide whether it should be the default.

https://scikit-image.org/docs/stable/auto_examples/color_exposure/plot_equalize.html