Use Splice.Amulet.CryptoHash functions directly once there available via rebase or merge

[adetokunbo]

Affects https://github.com/hyperledger-labs/splice/tree/adetokunbo/feature-cip-104-scan-computation
As of https://github.com/hyperledger-labs/splice/pull/4662` which adds db tests for these functions, they are inlined in the daml template that tests them
The inlined versions should be removed before the branch gets merged