Initial rendering of Add field option; need to figure how to suppress for built-in types
Refactor tests to make them easier to update when entity field default values change
Fix up lurking error in test cases (using non-existent type)
Simplify logic and fix setup inconsistencies in list view tests
Modified _children method to not return duplicate ids for entities in both collection and site data
Added logic for initializing new entities from per-type editable data; added initial fields for View entities; updated tests accordingly.