Make a "super actuator" method in DARMActuationModel / CALCSModel

It would be useful to have a method that has a sum of QUAD actuators, i.e., computing A_xn + A_yn for a given stage (n). Alternatively and in addition, have a method to compute A_mU + A_mP + A_mT. But building the full actuation response, we would use one or the other method, but not both.

The first method would be useful for computing \delta A_n that is currently being computed in calcs.py, and the second method would be helpful for computing the crossover math #77.

A similar method in CALCSModel would also be needed to maintain equivalency. See calcs_darm_actuation and gds_actuation_correction

Can be done after !118 (merged) is merged