Qualtran -> PyZX: First Tasks

[anurudhp]

towards #1517

#1550 implements the basic framework to generate a pyzx.Circuit from a bloq. Once it is merged, a natural first set of follow-up tasks would be:

• Override the as_zx_gates method for more leaf bloqs.
• Add more examples and tests (once they can be fully compiled)
• Notebook explaining the compilation to pyzx, with some examples.