Update the PfiTransform code to work with the correct fiducial positions

The PfiTransform code is used to map the measured fiducial positions onto the known positions, thereby putting the cobra positions onto that coordinate system.

With the corrected fiducial positions in use for the September 2022 run, the initial guess for this transform will be incorrect, so please change it.  The new values should be close to 0.0, but we should check that this is true.

We probably don't really need to do this, as the code should converge even starting at the old positions with suitable clipping parameters, but it'll be more robust if we make this change.

It is probably worth noting that the functional form of the best fit model could change once we've taken out this gross misalignment;  we should monitor this during the next few engineering runs.