Add `sha3` hashing function

[jbencin]

Add sha3 hashing function, which similar to Keccak (same algorithm with slightly different input parameters, as I understand it)

This should be trivial to do. Code structure and costs can be copied from the existing keccak256 function. It doesn't require any additional dependencies, since we use the sha3 crate for keccak256

I don't have an immediate need SHA3 in anything I'm working on, but I noticed Clarity doesn't have it, and IMO it's good to have broad support for cryptographic primitives since they are prohibitively expensive to implement in Clarity

[obycode]

Seems reasonable to me.