Improve the closure reports

Created by: wilsonmr

Since I am running some more closure tests I realised there were some improvements to make with the reports.

I added a table that summarises the t0 and fake pdf which helps when looking at the report. I added some trivial things like headings in the report.

Since some closure tests are ran based on hessian sets I wanted to be able to have all the distance plots - this required implementing the moments in core.py this should be checked

I was wondering if we wanted to be able to see delta chi2 by experiment? I'm not sure exactly how useful it is..