Add simulation backend for equivalent checking

[ChenZhao44]

We need an automatic test for equivalent checking. Previously I used YaoZX to test manually. Now, can we use BQCESubroutine? @Roger-luo

[Roger-luo]

In principle, yes, but we need to make it more stable before we use it for testing. We can also add a downstream test for YaoCompiler later.

[Roger-luo]

actually, I think we can just do a downstream test after integration with YaoCompiler, that's the easiest way of doing it.

[contra-bit]

#102 adds an equivalence checker for ZXDiagram