Wrapping Thrust for sorting

[kose-y]

Describe the solution you'd like
It would be great to have some of the unimplemented algorithms from Thrust, most prominently sorting. Most of the other algorithms provided seem to be already available through CuArrays.

Describe alternatives you've considered
There is an alternative wrapping CUB, but it seems to be a long way there according to this discourse discussion.

[maleadt]

Thrust is a C++ library that heavily relies on templates, wrapping it isn't straightforward right now. We basically need a C API, and I don't know of libraries like that. There's https://github.com/fynv/ThrustRTC, but that doesn't look very active.

[kose-y]

In my opinion, only a small subset of Thrust needs to be wrapped. Writing a short C++ code to make a C-style interface like in ThrustRTC sounds good enough to me. What do you think?

[maleadt]

I guess it's possible, but we would need to take care not to burden users that don't use CuArrays (but depend in it via, e.g., Flux). So probably using BinaryBuilder and lazy artifact instantiation. I don't have the time to work on that though, so feel free to take a shot yourself.

[maleadt]

We have a sort kernel now.