New Node Categorization System For Ontologies

[ecwood]

Part of #387, we want to update the node categorization system for ontologies, which is very flawed (ex. #367).

[ecwood]

The first step in this process is to identify the number of nodes in KG2c that are categorized from an ontology. (Based on discussion with @amykglen)

[ecwood]

While we didn't implement a completely new system, there is a much clearer node categorization system for ontologies that is easier to edit. Closing this issue