[Refactor] Switch to react-three-fiber

[tesseralis]

The app currently uses X3DOM which does what we want, but comes with some severe limitations:

• Has a fixed rotation system -- as far as I can tell, you can't "turn off" the ability to rotate the scene with the mouse, meaning we can't make scenes with, say, multiple polyhedra in a top-down view.
• Outdated, doesn't support builders and requires a custom webpack loader to run.
• Much smaller community than three.js

I've been meaning to switch to THREE.js for a while, and now that react-three-fiber exists it seems like the perfect opportunity!

The main issues for this are:

1. Creating a version of <PolyhedronGeometry> allows polyhedra with more than three vertices per face. (when I tried it out a while back, I couldn't figure out how to get the lighting to not light each of the coplanar faces separately.
2. Finding a control system that mimics X3DOM's (TrackballControls should work!)
3. replicating the current materials, colors, and options.

Moving to Three.js also means that we no longer need toxiclibsjs.