Add fuzz tests to show equivalence between stdlib cryptographic functions and rust implementations

[TomAFrench]

We should add some fuzz tests which generates random inputs and feeds them into the stdlib implementations of keccak256/sha256/etc. alongside an off-the-shelf rust implementation to give greater assurances about correctness.

Note that this won't work with just a regular fuzz test but will need a rust harness.

[TomAFrench]

proptest usage: https://github.com/noir-lang/noir/blob/be9dcfe56d808b1bd5ef552d41274705b2df7062/tooling/noirc_abi/src/lib.rs#L503C7-L503C8

exeuctor: https://github.com/noir-lang/noir/blob/be9dcfe56d808b1bd5ef552d41274705b2df7062/tooling/nargo/src/ops/execute.rs#L62

[TomAFrench]

compile from string snippet: https://github.com/noir-lang/noir/blob/be9dcfe56d808b1bd5ef552d41274705b2df7062/tooling/lsp/src/lib.rs#L332