Patch for mpi compilation on cyfronet Helios

[Caastlefox]

MPI compilation on Cyfronet-Helios environment required two changes
One change to prevent injection of CUDA macros into code by include
#include <boost/numeric/odeint/external/thrust/thrust.hpp>.
In files

libcloudphxx/src/lib_omp.cpp
libcloudphxx/src/lib_cpp.cpp

Second change modifies const into constexpr due to stricter compilation requirements in Cyfronet-Helios environment, where:

dynamic initialization is not supported for a __device__ variable

In C++ standard:
const is a read-only constant
constexpr is a guaranteed compile-time constant

It means static const class despite its name can be initialized dynamically, while __device__ class in Helios environment is required to be initialized statically.