Add a manage question behaviours admin page

As admin, use the manage question behaviours page 1. Make sure you can only delete behaviours that are not used. 2. Make sure that if you disable or re-order behaviours, that order is reflected in the choices available in the "How questions behave" form field in the quiz settings and question preview. Also, use the manage question types page 1. Check that the number of questions of each type links to the question instances report. 2. Check that you can only delete question types that are not in use. 3. Check that when you disable, or re-order question types, then that is reflected in the 'Add new question' UI.