Claim Graph & Archive URLs

[lautarodragan]

We have currently implemented a weak backwards compatibility for claims that have an archiveURL rather than an about.

It's a weak support, as it only works when the selected work is the one that has the archiveUrl.
That is, if a claim is made about a claim that has an archiveUrl, the graph will NOT show the referenced archive when a claim is selected in the graph unless that selected claim is the one that has the archiveUrl property.

In practice, that means that, if the graph includes an old claim, the archive will appear and disappear as the user navigates the graph by clicking on graph nodes.

Full support for old claims would require finding the roots of the graph, requesting those claims and checking them for an archiveURL property, rather than looking for it in the selected claim only.

A quick fix would be to not show the Make a Claim button when the selected claim has an archiveUrl rather than an about, basically disallowing the mixing of old and new claims.