remove unused GlobalDenseMatrix and DenseVector

MathLib/LinAlg/ApplyKnownSolution.h

MathLib/LinAlg/Dense/DenseTools.cpp

MathLib/LinAlg/Dense/DenseTools.h

MathLib/LinAlg/Dense/DenseVector.h

MathLib/LinAlg/Dense/GlobalDenseMatrix-impl.h

MathLib/LinAlg/Dense/GlobalDenseMatrix.h

MathLib/LinAlg/Sparse/CRSTools-impl.h

Tests/AssemblerLib/SteadyDiffusion2DExample1.h

Tests/AssemblerLib/TestVectorMatrixBuilder.cpp

Tests/MathLib/TestDenseGaussAlgorithm.cpp

Tests/MathLib/TestGlobalDenseMatrix.cpp

Tests/MathLib/TestLinearSolver.cpp

Tests/MathLib/TestMatrixAssemblyTemplate.cpp

Tests/MathLib/TestNonlinearNewton.cpp

Tests/MathLib/TestNonlinearPicard.cpp