Optics fitting wedge nut hole

The nut slot for mounting optics modules is orientated so that the nut goes in flat-first, whereas all other nuts in the microscope go in point first. Point first provides better support for the nut against turning.

This merge request rotates the nut in the cut-out module for the optics fitting wedge, while also maintaining the horizontal shaft in the correct orientation so that it is a printable horizontal hole.
fitting_wedge_cutout(z_pos=0, y_stop=false, nose_shift=0.2, max_screw=11); left is the old version, right is the new version.

This does make the nut fit better. The shaft hole has a rather large clearance because of the way that nut_y() is defined with the same parameter fudge adjusting the nut and shaft sizes.

closes #309 (closed)