Bindings were available only for linear systems of type CompressedRowSparseMatrix<SReal> and CompressedRowSparseMatrix<sofa::type::Mat<3,3,SReal> >.

This PR:

• Add support of vector access for all known linear system types where the vector type is FullVector.
• Extend the support of matrix access to other CompressedRowSparseMatrix
• Add support of matrix access for FullMatrix
• Duplicate respectively the function A(), b() and x(), to get_system_matrix, get_rhs_vector and get_solution_vector.