…-gpu into improve-2.0-dev-mpi

…<ConnKeyT, ConnStructT> derived classes, with specialized template class ConnectionTemplate<conn12b_key, conn12b_struct> 12 byte connections

…struct conn16b_struct (8 bytes)

…truct conn16b_struct (8 bytes)

…ak CUDA memory usage of each MPI process, total CUDA memory available for all MPI processes, free CUDA memory available for all MPI processes. Adapted MPI connections CUDA memory check scripts to run on terminal and to check used CUDA memory against theoretical prediction automatically

…ource host side

…-tidy. Prepared wrappers for clang-format and clang-tidy compatibility with CUDA / CUB headers and scripts to run formatting and checks on all source c++/cuda files.

…o find automatically CUDA and MPI default header paths or to accept user-defined path lists for include files, CUDA or MPI headers

…les with clang-format and check them with clang-tidy

…ce for connection structure is

… connection memory check through script benchmark_terminal.sh. Writing some comments on connection-related code.

…g on netgpu class parameters