GPU: Improvements for sorting / thrust external allocator

[davidrohr]

• Provide clean way to provide external allocator to thrust
• Move the thrust device-wide sorting to a function in GPUCommonAlgorithm, use from there
• And try to use cub instead of thrust for sorting (compile-time switch)
• Cleanup and simplification in a couple of places.

Unfortunately, this PR causes a major performance regression both on my NVIDIA GPU and on EPNs. I don't understand why yet. Just want to check it in the CI, and show @mconcas how to use the external allocator.

[github-actions]

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[davidrohr]

@mconcas : For using the thrust external allocator, see https://github.com/davidrohr/AliceO2/blob/c9e82dd6c8452852ea2e2eadfff5c4ac9887c901/GPU/Common/GPUCommonAlgorithmThrust.h#L96
You can query the allocator from GPUReconstruction, and then pass the object to thrust later. It works for both CUDA and HIP. Unfortunately, you have to pass the object around, there is no way around it.

The way it works is:

• You can use the allocator from GPUReconstruction::getThrustVolatileDeviceAllocator() to allocate "volatile" memory from the GPU pool.
• You can call GPUReconstruction::ReturnVolatileDeviceMemory() to return the memory to the pool.
• In the meantime, you must not use AllocateUnmanagedMemory(), that would lead to memory corruption. I'll add a protection in the future, but for now please be careful.
  Let me know if you think that this can work for you.

[davidrohr]

performance problem fixed

[alibuild]

Error while checking build/O2/fullCI_slc9 for c9e82dd at 2025-03-24 18:55:

## sw/BUILD/o2codechecker-latest/log
100% tests passed, 0 tests failed out of 1


## sw/BUILD/O2-latest/log
/sw/SOURCES/O2/14103-slc9_x86-64/0/GPU/Common/GPUCommonAlgorithmThrust.h:101:14: error: use of undeclared identifier 'hipcub'
/sw/SOURCES/O2/14103-slc9_x86-64/0/GPU/Common/GPUCommonAlgorithmThrust.h:103:14: error: use of undeclared identifier 'hipcub'
ninja: build stopped: subcommand failed.

Full log here.

[alibuild]

Error while checking build/O2/fullCI_slc9 for 9ceb34e at 2025-03-24 20:27:

## sw/BUILD/O2-latest/log
/sw/SOURCES/O2/14103-slc9_x86-64/0/GPU/Common/GPUCommonAlgorithmThrust.h:101:14: error: use of undeclared identifier 'hipcub'
/sw/SOURCES/O2/14103-slc9_x86-64/0/GPU/Common/GPUCommonAlgorithmThrust.h:103:14: error: use of undeclared identifier 'hipcub'
ninja: build stopped: subcommand failed.

Full log here.

[alibuild]

Error while checking build/O2/fullCI_slc9 for 471fdbf at 2025-03-25 00:08:

## sw/BUILD/O2-latest/log
CMake Error at GPU/GPUTracking/Base/hip/cmake_install.cmake:69 (file):
ninja: build stopped: subcommand failed.

Full log here.