Add -Wshadow

CMakeLists.txt

src/language/ast/ASTNodeDataTypeBuilder.cpp

src/language/utils/BuiltinFunctionEmbedderUtils.cpp

src/language/utils/DataVariant.cpp

src/language/utils/EmbeddedDiscreteFunctionMathFunctions.cpp

src/language/utils/ItemArrayVariantFunctionInterpoler.cpp

src/mesh/CartesianMeshBuilder.cpp

src/mesh/ConnectivityBuilderBase.cpp

src/mesh/ConnectivityDispatcher.cpp

src/mesh/DiamondDualConnectivityBuilder.cpp

src/mesh/Dual1DConnectivityBuilder.cpp

src/mesh/GmshReader.cpp

src/mesh/LogicalConnectivityBuilder.cpp

src/mesh/MedianDualConnectivityBuilder.cpp

src/mesh/MeshBuilderBase.cpp

src/mesh/MeshFlatNodeBoundary.cpp

src/mesh/MeshNodeBoundary.cpp

src/output/GnuplotWriter1D.cpp

src/utils/Partitioner.cpp

tests/mpi_test_main.cpp