Add local2eq dataset from aanet

This adds a test sample for coordinate transformations dx/dy/dz + UTM -> EQ

It also includes the script to generate the CSV file using aanet 2.7.0

The idea is to make sure that all the astro libraries (based on slalib, astropy, whatever) are converting in the same (correct) way.

@laphecetche @aheijboer can you have a look? I'd also like to add the galactic coordinates but had no time yet to look how it's correctly done with aanet.

Also note that I added a y2000 = true/false column, which is passed to EquatorialCoords