ADD automated Tests & visual tests

[gsimone]

Both should exist, eg.

// whatever.viz.jsx
// 1. passing viz
function ComponentWithVizUsingR3FProbably() {
	return <mesh>...</mesh>
}

// 2. non passing viz
...

// whatever.test.js
// regular jest stuff

Ideally, every fn in every entry point should have both visuals and unit (although visual is hard with stuff like determinants)