Test large arrays in in device radix sort

[alliepiper]

Description

closes #1268
closes #1348

Adds a new test utility that generates large (>2^32 elements) test inputs for sorting algorithms and verifies them, optimizing for runtime and minimizing host/device memory overhead.

Also adds large num_item test cases to radix sort tests in catch2 and removes the old legacy radix sort tests.

A new c2h::cpu_timer utility is also added that is useful for breaking down execution times of test cases per-step.

Looking at CI logs, this appears to increase the time needed to run CUB tests in CI by around 1 minutes (39m -> 40 min for gcc12/cuda12.3/c++17). The new large-input tests take longer than one minute, but their cost is offset by cleaning up some redundant small-input testscases.

[elstehle]

Thanks for the quick PR! I like the approach a lot for sanity checking large number of items. I'd be fine just being able to test keys for now as a best-effort approach to catching indexing issues, while halving memory requirements.

[alliepiper]

Looking at CI logs, this appears to increase the time needed to run CUB tests in CI by around 9 minutes (39m -> 48 min for gcc12/cuda12.3/c++17).

[alliepiper]

Time cost update after removing redundant tests using signed NumItemsT (cub::detail::ChooseOffsetsT automatically converts signed to unsigned):

Looking at CI logs, this appears to increase the time needed to run CUB tests in CI by around 1 minutes (39m -> 40 min for gcc12/cuda12.3/c++17).

Thanks @elstehle for pointing this out!

The new large-input tests do take longer than 1 minute to run, but this is offset by reducing the number of small-input tests.

[gevtushenko]

Great work!

[alliepiper]

Thanks for the excellent reviews! Should be all set to merge now once CI is green (current failure looks like an infra issue).

@elstehle I've updated the large array initialization methods to take a seed as suggested -- be sure to update your merge sort PR.