OCSADV-27: Declination limits and Coordinates Difference

On this PR the limits for declination or changed to allow 90 degrees and CoordinatesDiff is rewritten in Scala using the new model classes

I wish I could do more thorough tests but I couldn't find the source of the algorithm nor some well known table of differences to compare
Same thing here. Recomputing `abs` isn't expensive but it complicates the code. I would factor it out.