Support UUID version 6

[ancoron]

Is your feature request related to a problem? Please describe.

As an app developer, I want to generate version 6 UUIDs, so that I can use them in my database for indexes without too much trouble for scalability.

Describe the solution you'd like

UUID version 6 was created specifically for chronologically increasing identifiers, since existing UUID versions did not play very well with databases indexes at scale:

• https://www.rfc-editor.org/rfc/rfc9562.html#name-uuid-version-6

Describe alternatives you've considered

Using a different library, but I'd like to avoid yet another dependency just for this specific use case.

I'd rather contribute a first implementation.

[kt3k]

Thanks for implementing!