Add BLAKE3 support

[aumetra]

Closes #173

This PR adds support for using the BLAKE3 hash function as part of a Noise connection.
Unfortunately I'm not sure if there are any test vectors for it available.

But yeah, this adds a new hash state enum variant for BLAKE3 and adds support for it to the default provider.

[aumetra]

(sorry for the reformatting btw, VSCode config doing stupid stuff. I can revert it if wanted)

[mcginty]

Hey @aumetra thanks for the PR, and I'm interested in getting this into snow!