core/unit_test: separate cuda timing-based tests into separate exe

[ndellingwood]

To address issue #3405

[ndellingwood]

@crtrott @dalg24 since this change is pretty minimal, should it be cherry-picked to release-candidate-3.2.1 to get into Trilinos towards addressing trilinos/Trilinos#6799 ?

[crtrott]

Yeah

[masterleinad]

Looks reasonable.

[dalg24]

trilinos/Trilinos#6799 (comment) and
trilinos/Trilinos#6799 (comment) suggest to rename
UnitTest_Cuda3 -> UnitTest_CudaTimingBased
Why did you decide to create a new executable?

[dalg24]

To be clear I don't necessarily have a problem with your solution but you must comment that the changes you propose depart from the resolution that was suggested and why you suggested to do so.

[ndellingwood]

Why did you decide to create a new executable

@dalg24 the timing-based tests themselves were already part of the UnitTest_Cuda3 set of tests (which also includes non-timing based tests), so I separated them out into a new executable with the descriptive name UnitTest_CudaTimingBased that can be set to run serially for Trilinos projects that test with some level of parallelism (i.e. ctest -jN). I thought just renaming UnitTest_Cuda3 was a bit misleading since most of the tests do not rely on timing.