Poor support of CUDPP

[alxbilger]

SOFACUDA_CUDPP is a CMake option allowing to use CUDPP to scan or sort data on the GPU. Similarly, Thrust is used with the option SOFACUDA_THRUST. However, CUDPP dependency is not implemented in CMake. Therefore, activation of the option leads to a compilation error.

I suggest to add the dependency in CMake, or drop the support of CUDPP (it's a lib which the last commit is from 2016 https://github.com/cudpp/cudpp)