Blake2 optimization

[marcindsobczak]

Changes:

• added Blake2 computation in AVX2, SSE4.1 and scalar, adapted from Blake2Fast (https://github.com/saucecontrol/Blake2Fast)
• reduced computation time for Blake2 max rounds from >30min to <1min
• now we are passing CALLBlake2f_MaxRounds hive tests

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Other (please describe):

Testing

Requires testing

• Yes
• No

it is already tested, only the performance has increased.

[LukaszRozmej]

We could use a tests for 1-10 rounds for each method (AVX/SSE/Scalar) just to be sure we didn't miss any check