implement Decapsulate and Encapsulate from traits/kem

[incertia]

updates ml-kem as advertised. this keeps EncapsulateDeterministic inside ml-kem though, perhaps this trait also deserves promotion to kem?

[tarcieri]

This seems like a good start.

Perhaps open an issue about EncapsulateDeterministic on the traits repo?

[tarcieri]

Needs rustfmt and the trait isn't in scope everywhere it needs to be for the tests.

Also perhaps disable the minimal-versions check for now? Here's an example:

https://github.com/RustCrypto/traits/blob/25e5654bb0775d255abd937e3b3320b982f13da1/.github/workflows/elliptic-curve.yml#L62

[incertia]

Somehow adding the statement use ::kem::{Decapsulate, Encapsulate} still does not let the tests succeed

UPDATE: it seems like it was the doc test which confused me for more than I would like to admit

[tarcieri]

Looks like one more import is needed