Clean up type hinting

[billbrod]

In workshop, the type hinting for our methods was really really long, because NDArray was being fully expanded. There's a way to avoid this (I had this problem in plenoptic or pyrtools).

[billbrod]

Okay, turns out I had this problem in nemos. The solution is to add from __future__ import annotations to the top of the file. I've noticed this with the GLM, but it's possible it's showing up in other places as well.

However, then the type for X in the different GLM methods just reads: X: 'Union[DESIGN_INPUT_TYPE, ArrayLike]', and DESIGN_INPUT_TYPE is fairly opaque (ArrayLike is fine). what should we do?