Add broken cobra handling to the pfiDesign object.

Broken cobra tracking is currently ad-hoc (lists in code). We should load those into the pfiDesign object, since that is what tracks the configuration of the modules.

We could do this in two ways. There is a status field (unused?) in the XML file, which would keep all arm/module info in one file (good!). Or we could persist into a/the per-module YAML file in pfs_instdata. Inclined to use the status field for now; will look for any existing usage.

Will branch this off cit_freeze.