Provide an algorithm to polar sort mesh vertices

[agalbachicar]

A GeoFace is a collection of vertices and normals. Those vertices are supposed to live in the same plane. To get the correct triangulation and face orientation, we need to sort those vertices. Right now, the sort algorithm works with the vertices projection over the plane z = 0. This may work for most of the cases, but it will not cover any face which is over a normal plane to z = 0.