ENH: add helper classes to apply linear operations on pixels of a VectorImage

Code/BasicFilters/otbMatrixMultiplyImageFilter.h

Code/BasicFilters/otbMatrixMultiplyImageFilter.txx

Code/BasicFilters/otbUnConstrainedLeastSquareImageFilter.h

Code/BasicFilters/otbUnConstrainedLeastSquareImageFilter.txx

Code/BasicFilters/otbVectorImageToMatrixImageFilter.h

Code/BasicFilters/otbVectorImageToMatrixImageFilter.txx

Testing/CMakeLists.txt

Testing/otbHyperTests1.cxx

Testing/otbMatrixMultiplyImageFilter.cxx

Testing/otbUnConstrainedLeastSquareImageFilter.cxx