Merge branch 'feature/connectivity-improvements' into 'develop'

src/mesh/Connectivity.cpp

src/mesh/Connectivity.hpp

src/mesh/ConnectivityComputer.cpp

src/mesh/ConnectivityComputer.hpp

src/mesh/ConnectivityMatrix.hpp

src/mesh/IConnectivity.hpp

src/mesh/ItemArray.hpp

src/mesh/ItemArrayUtils.hpp

src/mesh/ItemId.hpp

src/mesh/ItemToItemMatrix.hpp

src/mesh/ItemValue.hpp

src/mesh/MeshData.hpp

src/mesh/PrimalToDiamondDualConnectivityDataMapper.hpp

src/mesh/PrimalToDual1DConnectivityDataMapper.hpp

src/mesh/PrimalToMedianDualConnectivityDataMapper.hpp

src/mesh/SubItemArrayPerItem.hpp

src/mesh/SubItemArrayPerItemUtils.hpp

src/mesh/SubItemValuePerItem.hpp

src/mesh/SubItemValuePerItemUtils.hpp

src/output/VTKWriter.cpp