Add ability to expand inactive folders to view its children

Currently in the i2b2 ontology views an inactive folder will display in the hierarchical tree but you cannot expand it to see the items contained within it.

This change will improve the functionality of inactive folders by allowing users to expand them within one of the Ontology views (Navigate, Find, and Edit Terms).

New Behavior:
* Inactive folders can be expanded (opened) to display its children.
* Inactive concepts that have a modifier associated to it can be expanded to display the modifier(s).


Existing Behavior that will not change:
* The color of inactive items will be gray when displayed in the hierarchical tree.
* Cannot drag an inactive item out of the Ontology views to another i2b2 view.
* Inactive items will not be returned in the Find Terms view.
* Editing Terms: As long as the term is defined as editable all editing functions will be available to inactive terms.