Merge branch 'develop' into feature/implicit-solver

src/mesh/ItemArrayUtils.hpp

src/mesh/ItemValueUtils.hpp

src/mesh/MeshNodeBoundaryUtils.cpp

src/mesh/SubItemArrayPerItemUtils.hpp

src/mesh/SubItemValuePerItemUtils.hpp

src/output/WriterBase.hpp

src/utils/Array.hpp

src/utils/SmallArray.hpp

tests/test_Array.cpp

tests/test_ItemArrayUtils.cpp

tests/test_ItemValueUtils.cpp

tests/test_SubItemArrayPerItemUtils.cpp

tests/test_SubItemValuePerItemUtils.cpp