Should the verifier always re-hash?

[huitseeker]

I think it would be better if we always unconditionally did the Sha256 hashing here, since this heuristic would be confusing to callers.

What about removing the if entirely and the assets/fibonacci_fixture.json test case?

Originally posted by @wwared in #4 (comment)

FG: What I'm thinking is that in the unfortunate case where the user has an Insanely long public value string, and does not want to put the pre-image check on-chain, if the verifier always requires re-hashing, there is no verifier that the user could make any use of.