PopupWindow: Fix escape with the Qt backend

With the Qt backend, the PopupWindow has it's own Window, so we need to
make sure we close the popup on the right Window

Fixes #7332

internal/core/window.rs

@@ -746,15 +746,26 @@ impl WindowInner {
             && event.text.starts_with(key_codes::Escape)
         {
             // Closes top most popup on esc key pressed when policy is not no-auto-close
-            let close_on_escape = if let Some(popup) = self.active_popups.borrow().last() {
+
+            // Try to get the parent window in case `self` is the popup itself
+            let mut adapter = self.window_adapter();
+            let item_tree = self.component();
+            let mut a = None;
+            ItemTreeRc::borrow_pin(&item_tree).as_ref().window_adapter(false, &mut a);
+            if let Some(a) = a {
+                adapter = a;
+            }
+            let window = WindowInner::from_pub(adapter.window());
+
+            let close_on_escape = if let Some(popup) = window.active_popups.borrow().last() {
                 popup.close_policy == PopupClosePolicy::CloseOnClick
                     || popup.close_policy == PopupClosePolicy::CloseOnClickOutside
             } else {
                 false
             };
 
             if close_on_escape {
-                self.close_top_popup();
+                window.close_top_popup();
             }
         }
         crate::properties::ChangeTracker::run_change_handlers();