[wish] Make sort2 and sort3 public

[wlinna]

Is there a reason to limit the visibility of sort2 and sort3 to pub(crate)? If not, I propose that the visibility would be changed to pub.

In my case they'd be useful for reimplementing some of the functions in parry. I use f32 version of parry, but occasionally need higher precision. In those cases I copy the original implementation and change f32 to f64. Not having these utility functions available means that I have to copy them too, and change the references.