Fixup bindings for hex serialization

[mrmr1993]

This PR updates the bindings for the latest changes to the proof-systems repo.

This

• uses the hex option for generating the poseidon test vectors
• updates the poseidon test to work correctly with hex strings as input and output
  • previously input was base-10, but output was hex!
• updates the serde rules to use is_human_readable: false, so that we don't generate hex strings for field elements across the FFI boundary

[querolita]

Looks good to me 👍🏻

[mitschabaude]

the serialization changes look good, but CI now fails in caml_pasta_fp_proof_of_rust:
https://github.com/o1-labs/snarkyjs/actions/runs/5203561513/jobs/9386575314

nit: you don't auto-format the code with prettier, maybe we should add a quick command to do so. but not important

[mitschabaude]

snarkyjs CI should work before landing this

CI now passes