Support composing and checking error #17
Description
gridsynth and pygridsynth can compose the string of gates and compute the operator norm distance between the resulting unitary and the desired rotation.
When developing, it is useful to know if and how well the gate string approximates the desired unitary (believe it or not). I present, I have to copy strings to another program to test.
DOmegaUnitary implements from_gates. It should be little effort to compute the error.