title: How to refresh a page after back button pressed
body: <p>I have a "list page". and an add page. User clicks "add page", goes to a new page where they add some entity. Then I pop the Navigator, and user goes back to "list page". </p>
  
  <p>At this point, I want to get notified somehow - callback maybe? override a method, I am not really sure - and re-read the information from database.</p>
  
  <p>Is there a hook like this in Flutter? Or is there another pattern that I should use?</p>