Make delegate component editable in Navigator and Properties view

Currently, a user has to edit the delegate in Code. But it'd be better if the delegate component shows up in the Navigator as a child to ListView, selecting which shows the property of the delegate, such as Text, to the Properties view.

This way, a user without coding experience c could make ListView easier without touching the code.

I attached the sample project which was tested with QDS 4.5.1.