Implement `crypto.diffieHellman()`

[littledivy]

[iuioiua]

I'll aim to have this done for 1.41.

[birkskyum]

Maybe https://crates.io/crates/x25519-dalek could be helpful here?

[birkskyum]

@littledivy is this and #13451 resolved after #24463 ? I'm trying to reassess the status on blockers for this SolidStart ticket (#23474).

[iuioiua]

To be completed in #24938.