Push squin -> stim rewrite errors to emission instead of raising immediately

[johnzl-777]

@weinbe58 pointed out it's better practice to just indicate a rewrite did not happen and let emission be the part of the compilation that throws exceptions. I currently have a number of potential issues I try to catch from analysis results that I understand should be delegated further down the line.

[johnzl-777]

See #148 and #179 , the idea is to have two verification passes instead, one that can verify the squin program by itself is correct and another to verify that a squin program can actually be successfully converted to Stim