enum: add --uuid7 option to create UUID v7 identifiers

[jqnatividad]

which are time-based and monotonically increasing now that the uuid v1.9.0 guarantees

let a = Uuid::now_v7();
let b = Uuid::now_v7();

assert!(a < b);

https://github.com/uuid-rs/uuid/releases/tag/1.9.0
https://buildkite.com/blog/goodbye-integers-hello-uuids
https://datatracker.ietf.org/doc/rfc9562/