Add BLAKE3 cryptographic hash function

[Coralesoft]

I saw the feature request and had some time, so I've added BLAKE3 support.

What's included:

• Full implementation of BLAKE3 hash function
• Standard hashing (default 32-byte output)
• Keyed hashing (MAC mode with 32-byte keys)
• Key derivation function (KDF mode with context strings)
• Variable-length output (1-1024 bytes) via extended output function (XOF)
• Merkle tree construction for efficient streaming
• Integration with the existing test suite

Testing:
I've verified the implementation against all official BLAKE3 test vectors
from the reference implementation:

• 1024-byte input (1 chunk)
• 2048-byte input (2 chunks, tree merging)
• 4096-byte input (4 chunks, full tree)
• Extended output (64-byte XOF)
• Empty string, short messages, keyed hashing

All test vectors passed.

Implementation notes:

• Based on the official specification at https://github.com/BLAKE3-team/BLAKE3-specs
• Uses ChaCha20-based compression function
• Implements lazy Merkle tree construction for streaming efficiency
• 1024-byte chunks with 64-byte blocks
• Fully integrated with cryptest.exe validation suite

Let me know if you'd like me to make any changes or if you have questions.

Thanks

Resolves #1313