[hasherSha256.nr] Convert bits to bytes, hash the concatenated inputs

[nullity00]

Noir Docs for SHA : https://noir-lang.org/standard_library/cryptographic_primitives/hashes/#sha256 Circom File : https://github.com/privacy-scaling-explorations/maci/blob/master/circuits/circom/hasherSha256.circom Noir File : https://github.com/nullity00/maci-noir/blob/main/src/hasherSha256.nr At the moment, Noir's Sha hash functions only hashes an array of bytes & gives an array of bytes.

To Do

• [ ] Helper functions to convert multiple Fields into an array of bytes
• [ ] Helper functions to convert bytes into Field Type
• [ ] Use the SHA hash here : https://github.com/nullity00/maci-noir/blob/main/src/processMessagesInputHasher.nr#L32