Support computing distance between half-spaces and some other shapes

[gywn]

This PR fills the missing template specialization of GJKSolver_libccd::shapeDistance and GJKSolver_indep::shapeDistance, which implement distance computation between half-spaces and some other geometries (spheres, capsules, and boxes) widely used in quasi-real-time collision checking.

These specializations are necessary because libccd's GJK solver suffers from segfaults as the half-space geometry does not have finite support.

This will stay as a contribution to the newer upstream if we were to merge the upstream, since the upstream differs from the current branch only in two newly implemented template specializations of sphere-box and sphere-cylinder distance calculation. c.f.

• https://github.com/flexible-collision-library/fcl/blob/master/include/fcl/narrowphase/detail/primitive_shape_algorithm/sphere_box.h#L130-L133
• https://github.com/flexible-collision-library/fcl/blob/master/include/fcl/narrowphase/detail/primitive_shape_algorithm/sphere_cylinder.h#L126-L130

[gywn]

@kanbouchou @snozawa