Categorize graphs on site by source

[caufieldjh]

The full list of graphs is very long, but could be navigated more easily by compressing some records (or at least placing them in the same table) on the basis of their source, e.g., all graphs that are part of KG-IDG or all KG-OBO graphs.
The KG-OBO graphs have the most version chaos going on as it is, so they may need their own page.