Redefine Edge Tubes, Medial Surface, and Cube Sides for Euclidean

[mtwoodard]

[mtwoodard]

This may be a bit of an issue as of now as many of the SDFs take parameters that aren't useful for Euclidean space. Function overloading is a possible solution here or if we can somehow fit what we need in Euclidean space in to the predefined parameters that could work as well.

[roice3]

I'll take this one (assigning to myself now). I've been thinking some about it, and am leaning towards trying to make it fit. For example, the "dual point" of a plane in the Euclidean case could be the plane normal.

I want to the solution work for the spherical case as well.