* Hash to Curve: impl expand_message_xmd
* Try to precompute part of hash to curve at compile-time
* sha256 bench - use the new hashes module
* [WIP] smoke test hash to field
* Implement hash_to_field with expected output
* unoptimized hash-to-curve G2 for BLS12-381
* Don't run sanitizer on hash to field as it uses GC-ed strings
Mamy Ratsimbazafy