Add busy count for integration tests

Integration tests need to be notified when Lazygit is idle so they can progress to the next assertion / user action.

pkg/gui/layout.go

@@ -114,6 +114,8 @@ func (gui *Gui) layout(g *gocui.Gui) error {
 			return err
 		}
 
+		gui.handleTestMode()
+
 		gui.ViewsSetup = true
 	}