chore: use root navigator for popup menus

lib/pangea/chat/widgets/pangea_chat_input_row.dart

@@ -213,6 +213,7 @@ class PangeaChatInputRowState extends State<PangeaChatInputRow> {
                         clipBehavior: Clip.hardEdge,
                         decoration: const BoxDecoration(),
                         child: PopupMenuButton<String>(
+                          useRootNavigator: true,
                           icon: const Icon(Icons.add_outlined),
                           onSelected: _controller.onAddPopupMenuButtonSelected,
                           itemBuilder: (BuildContext context) =>

lib/pangea/chat_settings/pages/pangea_chat_details.dart

@@ -524,6 +524,7 @@ class RoomDetailsButtonRowState extends State<RoomDetailsButtonRow> {
                 }
 
                 return PopupMenuButton(
+                  useRootNavigator: true,
                   onSelected: (button) => button.onPressed?.call(),
                   itemBuilder: (context) {
                     return otherButtons