[Fix] MultiGPU Refinement

.gitignore

apps/benchmarks/NonUniformGrid/NonUniformGrid.cpp

apps/benchmarks/NonUniformGridCPU/NonUniformGridCPU.cpp

...s/NonUniformGridCPU/simulation_setup/benchmark_configs.py

apps/benchmarks/NonUniformGridGPU/NonUniformGridGPU.cpp

...s/NonUniformGridGPU/simulation_setup/benchmark_configs.py

python/pystencils_walberla/codegen.py

python/pystencils_walberla/kernel_info.py

python/pystencils_walberla/kernel_selection.py

src/blockforest/BlockForest.h

src/blockforest/SetupBlockForest.h

src/blockforest/StructuredBlockForest.h

src/blockforest/communication/NonUniformBufferedScheme.h

src/core/mpi/BufferSystem.h

src/core/mpi/BufferSystem.impl.h

src/core/mpi/BufferSystemHelper.impl.h

src/core/mpi/OpenMPBufferSystem.impl.h

src/gpu/communication/CustomMemoryBuffer.h

src/gpu/communication/GeneratedNonUniformGPUPackInfo.h

src/gpu/communication/NonUniformGPUScheme.h