Need methods in sensing, actuation, calcs modules

In the sensing module, we have a method called sensing_residual (aka C_res, or C_r in T1900169) which is the entire sensing path with the optical response divided out. We need an analogous method in actuation to compute the residual actuation (aka A_r) that is the actuation function with the low frequency response and dynamical response divided out (this is making the assumption that the CALCS installed dynamical response is perfectly representing the true dynamical response).

See LHO aLOG 63607 for what should be left in each of C_res and A_res (in the aLOG these are referred to as dC and dA)

We already have a method in the CALCS module that computes the CALCS representation of A (aka A_f), we need an analogous in CALCS to compute the CALCS representation of C (aka C_f).