Seems like an essential part of the toolbox -- we have Point, LineSegment
and Line and now we have also all "swept sphere" alternatives to them --
Sphere (swept "along" the point), Capsule (swept along line segment) and
Cylinder (swept along infinite line).
"Implemented" collision detection with point and sphere, which is just
simplified version of collision detection implemented for Capsule (i.e.
no need to check for cap cases).
Capsule, Sphere and Plane would behave weirdly if non-uniform scale
would be applied to them. This restriction allows to use more performant
code (i.e. less normalization and matrix multiplication). Updated the
tests to verify that uniform scaling is handled well, for Capsule and
Sphere there is now also no need to test both 2D and 3D transformation.