Fixes#5192.
@liamsi Can you verify that the test vectors match the Rust implementation? I updated `ProofsFromByteSlices()` as well, anything else that should be updated?
## Description
This PR removes simple prefix from all types in the crypto/merkle directory.
The two proto types `Proof` & `ProofOp` have been moved to the `proto/crypto/merkle` directory.
proto messge `Proof` was renamed to `ProofOps` and `SimpleProof` message to `Proof`.
Closes: #2755