No higher order quad elements in FEniCS2019

[gtpash]

FEniCS 2019.1.0 cannot handle higher order quadrilateral elements, so the FeatFlow DFG2D-3 benchmark cannot be used since Q2-P1 elements are not an option like it is in dolfinx. Perhaps DFG2D-1 could be implemented with Taylor-Hood (P2-P1) elements.