Add structure and BC descriptor for Rusanov composite scheme

.gitignore

src/language/modules/SchemeModule.cpp

src/mesh/MeshData.hpp

src/scheme/CMakeLists.txt

src/scheme/IBoundaryConditionDescriptor.hpp

src/scheme/InflowListBoundaryConditionDescriptor.hpp

src/scheme/RusanovEulerianCompositeSolver.cpp

src/scheme/RusanovEulerianCompositeSolver.hpp

tests/test_TestVolumes3D.cpp