chore: update package-lock.json after repo flattening (#645)

### Summary

I noticed some changes in `package-lock.json` after running `npm
install` so here I just deleted `package-lock.json` and started fresh
with a new one.

This results in some additional updates packages but tests pass and
examples work.

Edit: updates to gl-matrix and TypeScript resulted in some new warnings,
which are also resolved here. Notably the `mat4.invert` return type now
(correctly) indicates it can return `null` for non-invertible matrices.
All our transforms should be (better be!) invertible.

Author: aganders3