Refactoring sparse matrices: setting row lengths via VectorView

src/Python/pytnl/tnl/SparseMatrix.h

src/TNL/Matrices/AdEllpack.h

src/TNL/Matrices/AdEllpack_impl.h

src/TNL/Matrices/BiEllpack.h

src/TNL/Matrices/BiEllpackSymmetric.h

src/TNL/Matrices/BiEllpackSymmetric_impl.h

src/TNL/Matrices/BiEllpack_impl.h

src/TNL/Matrices/COOMatrix.h

src/TNL/Matrices/COOMatrix_impl.h

src/TNL/Matrices/CSR.h

src/TNL/Matrices/CSR_impl.h

src/TNL/Matrices/ChunkedEllpack.h

src/TNL/Matrices/ChunkedEllpack_impl.h

src/TNL/Matrices/Dense.h

src/TNL/Matrices/Dense_impl.h

src/TNL/Matrices/Ellpack.h

src/TNL/Matrices/EllpackSymmetric.h

src/TNL/Matrices/EllpackSymmetricGraph.h

src/TNL/Matrices/EllpackSymmetricGraph_impl.h

src/TNL/Matrices/EllpackSymmetric_impl.h