Add matlab code for simulated PLDS control

[mfbolus]

Is your feature request related to a problem? Please describe.
There is a method for simulating feedback control with GLDS objects, but there is no such function for PLDS.

Describe the solution you would like.
Add a complimentary method to matlab/@plds.

Describe alternatives you have considered.
No real alternative unless we remove the feedback control simulation from GLDS.

Additional Context
N/A