Add sort function to std

[TheLostLambda]

Not certain which algorithm we'd want to use, but I was very surprised to not find any sorting functions in std! It seems like a super common operation and there are a number of algorithms already in the tests/ folder.

Is there a reason these haven't been added already? Is it the sort of thing that you'd be interested in me adding via a PR?

P.S. Koka is probably the most elegant language I've ever come across — it's very exciting to see so much innovation in the functional programming space and research put into practice!

[TheLostLambda]

We might want to start with something simpler, but if we're eventually interested in some decently state-of-the-art stuff, then there is some great information about the sort algorithms that replaced those in the Rust standard library a few months ago: rust-lang/rust#124032

Stable sort: https://github.com/Voultapher/sort-research-rs/blob/main/writeup/driftsort_introduction/text.md
Unstable sort: https://github.com/Voultapher/sort-research-rs/blob/main/writeup/ipnsort_introduction/text.md