[FEA]: Remove all raw cudaMalloc, cudaHostMalloc, cudaFree, etc calls in CUB catch2 tests with c2h vectors.

[alliepiper]

Is this a duplicate?

• I confirmed there appear to be no duplicate issues for this request and that I agree to the Code of Conduct

Area

CUB

Is your feature request related to a problem? Please describe.

I've encountered a number of memory leaks in CUB's tests stemming from the use of cudaMalloc, cudaHostMalloc etc with missing frees.

Describe the solution you'd like

RAII containers, ideally c2h vectors, should be used instead. If needed, new ones like c2h:::pinned_vector should be added.

Describe alternatives you've considered

No response

Additional context

No response