Specify Blake3's derive_key algorithm instead of SHA3

[matheus23]

• Use Blake3 instead of SHA3 everywhere
• Use the derive_key algorithm from blake3 (see the specification) if applicable
• Introduce some domain separation strings to use with derive_key
• Adjust the way external file content blocks are linked to skip a lot of work.

❗ merge order ❗

1. Update rsa modulus endianess to match most protocols #66
2. Remove namefilter.md and add NameAccumulator verification algorithm #68
3. This PR
4. Switch from AES-GCM to XChaCha20-Poly1305 #70
5. Add baseName to ExternalContent #71

[expede]

Nit: we should probably use the all-caps BLAKE3, as that's the algorithm name

[expede]

Also, what happened to he font size? Super minor, but I think the larger font was easier to read (bigger is almost always beter, espeically with colour)

[matheus23]

Yeah. Font size changed because tldraw version was updated :/
I'd need to rework the diagrams a bit and resize stuff to have better proportions. But yeah, that's what I get for using the beta 🙃

[expede]

I wish Mermaid had more control over layout, but 🤷‍♀️

[matheus23]

I fixed the BLAKE3 spelling, but I hope it's okay if I postpone the diagram adjustments.
It takes quite a while creating these diagrams, and there's a bunch of things that should be done at the same time, that includes switching over to one consistent style for diagrams for example.

[expede]

+1,052 −1,191

LOL I guess TLDraw makes big diffs

Just a couple minor suggestions, but otherwise looks good :)