[test][distance] cleanup common code for distance unit tests in the
spherical_equatorial coordinate system
[test][distance] add algorithm (used in unit tests) for computing the distance
in a brute force manner, using BG's distance only for the following combinations:
* point/point
* point/segment
* segment/segment
[test][algorithms][distance] cleanup unit test for distances of
pointlike/pointlike geometries in the spherical equatorial coordinate system;
add testing when a comparable strategy is passed;
[test][algorithms][distance] add unit test for testing distance
computations for pointlike/linear geometries in the spherical equatorial
coordinate system
Merge pull request #180 from mkaravel/feature/distance

Feature/distance