Functional search issues

The following functional issues were found when interacting with search through the UI:

- Groups and content always return a 'extra' property with 'null' value, which shouldn't be necessary. Users don't have the 'extra' property, but they should.

- Is there any chance that we can rename the 'title' property with something that's consistent with the models? If not, can we rename the models to have a title property?

- Users don't have a resourceType property.