Removed 'const' from definitions for consistency with the declarations

src/TNL/Algorithms/MemoryOperationsCuda.hpp

src/TNL/Algorithms/MemoryOperationsHost.hpp

src/TNL/Algorithms/MemoryOperationsSequential.hpp

src/TNL/Algorithms/MultiDeviceMemoryOperations.h

src/TNL/Algorithms/Multireduction.hpp

src/TNL/Algorithms/reduce.h

src/TNL/Benchmarks/Benchmarks.hpp

src/TNL/FileName.h

src/TNL/FileName.hpp

src/TNL/Meshes/GridDetails/Grid1D_impl.h

src/TNL/Meshes/GridDetails/Grid2D_impl.h

src/TNL/Meshes/GridDetails/Grid3D_impl.h

src/TNL/Meshes/Mesh.hpp

src/TNL/Meshes/MeshEntity.hpp

src/TNL/String.hpp