[REG 3.5.1 -> 3.6.0] Creator can't handle Qt Quick UI project

Create a new Qt Quick UI project.
In Projects view, you'll only see the project's name but no contained files:

Opening an existing project doesn't work either.

The project should be opened and all its files should be listed. This works correctly in Qt Creator 3.5.1.

Found and tested by Squish test tst_qml_locals.