Decide on on which metrics in modelCIF or linked to it

[keiran-rowell-unsw]

Description of feature

Because modelCIF is test things like PAE matrices for large complex can get very large.

The way around that is to 'associate' a file (.npz) in the metrics field. This alleviates the sizes issue. However there are two drawbacks:

• The format of the associated PAE file isn't guaranteed to the be the same for all the various programs, unlike numbers-in-text of some form
• Passing along the modelCIF file doesn't also bring with in the PAE data etc to be viewable in a program, like ChimeraX's modelcif function