Update res_p_field during stag. iter. convergence check

During stag. iter. convergence check at step n+1 the residuals of the displacements are updated with the new p_field value, however the res_p_field are not updated with the new strain_en_undegr (that is still the value computed using displ at the iter n). Make it sense to update also res_p_field?

Pro:

• most correct value of the residuals Cons:
• it takes another loop over the mesh and another integration
• updating should not change much