Add modern algorithms

[noraj]

• blake2 rfc7693: blake2b, blake2s
• SHA3 (Keccak) and SHAKE: sha3_224(), sha3_256(), sha3_384(), sha3_512(), shake_128(), shake_256()

[kotovalexarian]

Be careful with naming. What some people call SHA3 is actually a draft version of it, now known as Keccak. It's what Ethereum uses AFAIR. Final SHA3 is different. Maybe they both may be implemented under their proper names.