Puzzle of Evil box with 4x2 mm magnets

Enlarged the holes for the magnets to fit 4 mm diameter x 2 mm height magnets, since I had a few of those available. The rest is unchanged, so see the original thing description https://www.thingiverse.com/thing:4039896

I used FreeCAD to edit the mesh, which was a good learning experience using the possibility to explode a generated shape to allow the creation of two separate solids.