New option to compare apertures plots for pre_delivery_data

[mgennaro]

The current default for pre_delivery_data is to prepare separate plots for selected apertures from the "base" version of SIAF and the "new" (i.e. pre_delivery) version. In some cases it would be useful to have the ability to see 2 versions ("base" and "new") of the same aperture plotted on the same plot (e.g. to see the aperture move).

A simple proposed pseudo-code implementation using the aperture.plot method could be:

selected_apertures = ['aperture_1', ...'aperture_N']
for ap_name in selected_apertures:
    for siaf,siaf_name in zip([new_siaf,old_siaf],['name_new_siaf,'name_old_siaf']):
        ap = siaf.apertures[ap_name]
        ap.plot(fill=False,mark_ref=True,ax=ax)
        lines.append(ax.lines[-1])
        labels.append(siaf_name)
    
   ax.legend(lines,labels,fontsize=9,ncol=2)