Added warning if no SIMD instruction could be determined, adapted field layouts in all tests and benchmarks

use cuda as a first level language in CMake with `enable_language(CUDA)`
enable tests where cuda and codegen are both activated
various minor fixes

This new function does the actual generation using pystencils and creates a target library that can be used as a dependency as usual. One should not list the python script itself anymore in add_executable.
Convention: Use the AppName as a prefix for the generated lib!

Example Usage:

waLBerla_generate_target_from_python( NAME AppNameGeneratedLib FILE GenerateKernel.py OUT_FILES Kernel.h Kernel.cpp)

waLBerla_add_executable ( NAME AppNameGeneratedLibTest DEPENDS GeneratedLib)

To remove code duplication the distinction is now moved
into the generator. Default kernels are "with shape".

Added hydrodynamic force notifications, introduced them to tests and benchmarks, minor documentation and include fixes

Added AMR single settling sphere benchmark, removed necessity for ParMETIS to build AMRSedimentSettling, minor refactoring

COPY -> ON_GHOST_CREATION
MIGRATION -> ON_OWNERSHIP_CHANGE

Added lbm-mesa_pd coupling to have a fluid-particle coupling to the new rigid particle dynamics simulations