ed25519: Add wycheproofs

[pinkforest]

• Generate wycheproof driven static tests
• Machine generated wycheproof test cases for ed25519-dalek sorted by tc#
• If any wycheproof is added / modified / deleted this can be seen via diff easily readable via PR
• Tests reflect actual Rust code for actual test without worrying too much test case didn't get generated / correctly
• Comments from wycheproofs relayed to comments for quick reference & clarity

Problem by dynamically adding tests at runtime is these can be missed silently if the dyn generation fails - google doesn't add / modify / remove them much in any case so can just re-generate & check em in when needed 🤷‍♀️

wycheproofs-ed25519-dalek is excluded from workspace --all-features so it doesn't barf with the ed25519-dalek/legacy_compatibility -

It still gets tested by default features OK via workspace

Notes

Testing whole workspace with --all-features enables every feature from ed25519-dalek dependency despite wycheproofs-ed25519-dalek not explicitly including it due to how the resolver works within workspace.

Namedly ed25519-dalek/legacy_compatibility causes barf at wycheproof expanded generated.rs tc 63 and 85 fails

repro @ 4af5275
workspace_root $ cargo test --target x86_64-unknown-linux-gnu --features legacy_compatibility

So tests worked I guess :]

Follow-Ups

I will also send another PR to turn the VALIDATION_CRITERIA into static tests directly from C2SP/CCTV/ed25519/vectors.json and some sort of checksumming / commit following thing perhaps to follow modulo easily

[koba-e964]

Maybe adding publish = false may help because the crate looks primarily for testing and not meant to be used by other people.