Profile and optimize hot code paths

[crizCraig]

We currently have a lot of TODO's in the code around using Numba to accelerate various things like denormalizing actions, g-force calculations, and physics stepping, but I'm not really sure where the slowness is right now. We need to profile, unit test, and optimize hot paths as much as possible to speed up training which already takes a day or so. This video provides a good overview of how to do so with Numba, which is already used extensively throughout the project.