Add option for origin offset to scripts

[Werni2A]

Some packages have their pickup point for pick and place machines not in the center of the footprint but shifted by an offset. I think at the moment it is not possible to generate 3D packages with this requirement. At least for the Converter_DCDC script but I haven't found this functionality in other scripts either.

KLC F6.2 says that the footprint anchor should be placed at the pickup point and KLC M2.2 tells that the 3D models must be placed with an offset of (0, 0). This means that the 3D model needs to be shifted in the python scripts.

I can imagine that this is not too difficult when the coordinate origin is shifted by the specified offset but I have no idea how to perform this in FreeCAD therefore, I will leave this task to someone else.

Murata's NXE2 series is an example where this is necessary: