keyboard: Set ornament on selected item in OSK languages popup menu

There is no hint about the currently selected language, but this exists
in the mockups. Add a dot ornament on the language that is currently
selected at the time of showing the OSK languages popup.

Since this popup is created from scratch every time it is shown, and
the popup is torn down with the OSK during replacement. This also
works for further times the languages popup is shown.

Closes: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/5598
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2346>

js/ui/keyboard.js

@@ -244,6 +244,9 @@ var LanguageSelectionPopup = class extends PopupMenu.PopupMenu {
                 inputSourceManager.activateInputSource(is, true);
             });
             item.can_focus = false;
+            item.setOrnament(is === inputSourceManager.currentSource
+                ? PopupMenu.Ornament.DOT
+                : PopupMenu.Ornament.NONE);
         }
 
         this.addMenuItem(new PopupMenu.PopupSeparatorMenuItem());