predicates: implement predicates for delaunay

Created by: Bastiantheone

This PR is the first step for the delaunay implementation. It provides a package for the geometric predicates.

First this implementation uses float64 values to determine the orientation and if a point is in a circle. If the point is too close to 0 the calculation is reevaluated using big/Rat values. I still need to figure out a good value that determines when it is too close to 0. When researching this topic I saw that some people determine this value dynamically, based on the input values. Does anyone have any suggestion here?