Cleanup model utils

Just some refactoring.

I'm working on getting rid of rendr.entryPath and the modelUtils is the last place I have to tackle. (https://github.com/givingstage/rendr/tree/remove_global_entry_path)

This was just some (somewhat subjective) cleanup I decided to do. It's best to go through this pull request one commit at a time because they're somewhat unrelated to each other.