Injected value not shown in the comparison plots

When running summarypages on a set of PE runs corresponding to injections and providing the injection file (.json file, like the attached one) injection_bo.json the plots of the individual runs provide the vertical line corresponding to the injected value, but not the comparison plots.

I think it would be really useful to have that vertical line corresponding to the injected value in the comparison plots, as it would help to easily compare the different posteriors w.r.t. to the injected value. However, I do not know if this is easy to implement or if it would crash existing features.

Tagging also @roberto.cotesta as he has looked into it in the past and maybe he can shed some light on this.