The squeezer model now includes a power stabilization servo for driving a green AOM.

The following features were added to the TwinCAT code:

1. Renamed the flipper in the homodyne path from SQZ-SPARE_2 to SQZ-HD_FLIPPER.
2. Use OPO_IR_PD for the photodetector that measures the red light coming from the OPO to SQZT6, when the HD flipper is closed.
3. A way to select the double resonance condition: either CLF RF demod power or IR power, if a seed beam is used.
4. Enabled the readback of the PFD which is used lock the beat note, FIBR_PD_RF158, and the LO.