Introduce an optional dependency on SciPy to calculate convex hull
Introduce an optional dependency on SciPy to calculate convex hull

SciPy has a C++ backed implementation of convex hull calculation that is
faster and properly releases the GIL. If it is available, we now use it
though we can fall back to a non-scipy version.

Contributes to CURA-358

onitake/Uranium,onitake/Uranium