Customizable Accurate Hilbert Cube

This version of the Hilbert Cube has undergone some code refactoring allowing you to accurately specify the cube's information (in mm).

The example cubes follow the naming format "Hilbert-Iterations-CornerSize-GapSize-BeamSize.stl", so "Hilbert-2-5-10-3.stl" would represent a cube with 2 iterations, a corner size of 5, a gap size of 10, and a beam size of 3.

Due to a technical limitation of OpenSCAD, it is impossible to generate a cube with 5 or more iterations.

Inspired by https://www.