When mirroring framework, make "Internal associations" link

[jmarks]

When mirroring case.smarterbalanced.net, there are internal associations between the framework (e.g. the content spec links to the item specs at the target level). Also there are association from the source to items that are resident. In both cases the associations on the left column are not linked. They should be.

see and example here: https://opensalt.net/cftree/item/1127804

[roverwolf]

The listed associations in question do not have "linkable" destinations.

This is actually caused by technically invalid data from the framework being mirrored.

https://case.smarterbalanced.org/cftree/item/118333 shows that those associations are to URNs which are not CASE CFItems nor CFDocuments (they are tags to AIR and DOK identifiers).

The solution going forward is not obvious:

• I'm assuming that throwing an error during mirroring (and not mirroring) is not wanted
• Fetching the framework from OpenSALT.net currently returns those associations, but to filter them out would mean changing the data from what is being mirrored (so breaking the "mirror")
• The UI does not break, but could possibly be made to look nicer for these non-valid URNs (but is it worth the effort for something that is not valid data)