Added generic sha256

[Braqzen]

Closes #1511

[nfurfaro]

The implementation looks good :)
I'd like to see some tests for hashing different types added to the stdlib's test_projects/hashing before merging though.

[Braqzen]

The implementation looks good :) I'd like to see some tests for hashing different types added to the stdlib's test_projects/hashing before merging though.

Sure, I already have some assertions that can be compared to hash_u64. I don't know what a good test would be for the generic types of structs / enums. In my testbed I have the digest and output to compare against but I cannot actually tell if they are correct

[adlerjohn]

The unfortunate only way to test hashing is to go on some online hashing site and put in a few values, then use those values as test vectors.

[mohammadfawaz]

The unfortunate only way to test hashing is to go on some online hashing site and put in a few values, then use those values as test vectors.

Can we not use a hashing library such as https://docs.rs/sha2/latest/sha2/ in the hashing test? That's what I was hoping we'd accomplish for #1492, and this PR seems like the perfect place to knock that issue out.

Also, we can now deprecate (or even remove) hash_u64 and hash_value.

[adlerjohn]

Can we not use a hashing library such as

Ah, I meant if you wanted to test using only a Sway script and no Rust harness.

[mohammadfawaz]

Excellent PR. I appreciate the thorough testing!

[mohammadfawaz]

LGTM! I'd like another set of eyes to review this and I'll approve after.

[adlerjohn]

nit