Rename files according to the class names

src/language/modules/MeshModule.cpp

src/main.cpp

src/mesh/CMakeLists.txt

src/mesh/DiamondDualMeshBuilder.cpp

src/mesh/DualConnectivityManager.cpp

src/mesh/DualConnectivityManager.hpp

src/mesh/DualMeshManager.cpp

src/mesh/DualMeshManager.hpp

src/mesh/IConnectivity.cpp

src/mesh/IMesh.cpp

tests/mpi_test_main.cpp

tests/test_CellIntegrator.cpp

tests/test_EdgeIntegrator.cpp

tests/test_FaceIntegrator.cpp

tests/test_main.cpp