SHA2 Compress Function

Pure Rust implementation of SHA2 compress functions.

• [x] SHA256
• [x] SHA224
• [x] SHA512
• [x] SHA384
• [x] SHA512/256
• [x] SHA512/224

TODO

Investigate

• https://en.wikipedia.org/wiki/IntelSHAextensions and
• https://developer.arm.com/documentation/ddi0500/e/functional-description/about-the-cortex-a53-processor-functions/cryptography-extension