Merge antidunes app into master

.gitlab-ci.yml

apps/showcases/Antidunes/Antidunes.cpp

apps/showcases/Antidunes/Antidunes.prm

apps/showcases/Antidunes/AntidunesBoundaryHandling.h

apps/showcases/Antidunes/AntidunesBoundaryHandling.impl.h

apps/showcases/Antidunes/AntidunesLatticeModelGeneration.py

apps/showcases/Antidunes/BedGeneration.cpp

apps/showcases/Antidunes/BedGeneration.prm

apps/showcases/Antidunes/CMakeLists.txt

apps/showcases/Antidunes/PIDController.cpp

apps/showcases/Antidunes/PIDController.h

apps/showcases/Antidunes/Utility.h

apps/showcases/Antidunes/pyvista.ipynb

apps/showcases/Antidunes/slice_evaluation.ipynb

apps/showcases/CMakeLists.txt

src/lbm/blockforest/communication/SimpleCommunication.h

src/lbm/free_surface/InitFunctions.h

src/lbm/free_surface/InterfaceFromFillLevel.h

src/lbm/free_surface/VtkWriter.h

...coupling/momentum_exchange_method/boundary/CurvedLinear.h