Implement a Z Scaling Factor option

[javicasarias]

What new features would you like to see implemented?
Include an additional option in the preferences window to apply a Scaling Factor to the estimated z positions.

Can you provide some motivation for why this feature should be added?
The refractive index missmatch between the coverglass and the sample should be taken into account for 3D MINFLUX measurements.

Describe the solution you'd like
An additional textbox in the preferences window to indicate the desired value.

Additional context
This correction is not applied to the raw data exported from Imspector, and should be done during post-processing as indicated in the literature.