Check if we should flatten rotations to U with helper methods

[chemix-lunacy]

Currently our Gate instructions have CX, X, etc when they could likely be squashed to just U and CU. But there's also the opposite question: is U too close to the physics and should we pull back and just call it an X rotation? Answer is likely no, but should be considered.

Investigate whether flattening one way or the other has distinct benefits, keeping both is duplication right now.