[Measure] Remove unused properties from measure preferences

[hlorus]

Remove leftover "Mirror" and "DistanceFactor" properties from measure preference dialog.

Closes #13805

[furgo16]

Thanks. Do they need to be removed from the location pointed at https://github.com/FreeCAD/FreeCAD/issues/13805#issuecomment-2092520698 (and the corresponding header file) as well?

[hlorus]

Thanks. Do they need to be removed from the location pointed at #13805 (comment) (and the corresponding header file) as well?

Yeah why not, thanks for the hint.

[maxwxyz]

@hlorus off topic: The text in the task dialog "Mode:" and "Result:" does not appear for translation, is this correct?