rename CoProcessor to SimulationObserver

apps/cpu/ConvectionOfVortex/cov.cpp

apps/cpu/CouetteFlow/cflow.cpp

apps/cpu/FlowAroundCylinder/cylinder.cpp

apps/cpu/HerschelBulkleyModel/hbflow.cpp

apps/cpu/HerschelBulkleySphere/hbsphere.cpp

apps/cpu/JetBreakup/JetBreakup.cpp

apps/cpu/LaminarTubeFlow/ltf.cpp

apps/cpu/Multiphase/Multiphase.cpp

apps/cpu/MultiphaseDropletTest/droplet.cpp

apps/cpu/PoiseuilleFlow/pf1.cpp

apps/cpu/RisingBubble2D/RisingBubble2D.cpp

apps/cpu/ViskomatXL/viskomat.cpp

apps/cpu/rheometer/rheometer.cpp

apps/cpu/sphere/sphere.cpp

src/basics/geometry3d/CoordinateTransformation3D.h

...u/LiggghtsCoupling/LiggghtsCouplingSimulationObserver.cpp

...cpu/LiggghtsCoupling/LiggghtsCouplingSimulationObserver.h

src/cpu/VirtualFluids.h

src/cpu/VirtualFluidsCore/BoundaryConditions/BCArray3D.h

...VirtualFluidsCore/BoundaryConditions/BoundaryConditions.h