Right now we allow you to change the item of a typed list without impacting the items. If the list is changed to anything but Z1, any existing items could be no longer valid. We should:
- show a warning to the user when they change the type of a list (similar to what the function definition page does when changing the type of an input/output)
- on publish, remove all items from the list if the type has changed (to anything but Z1)