Improve dropdown menu keyboard navigation (#11491)

* Allow selecting menu items with the space bar in status dropdown menus

* Fix modals opened by keyboard navigation being immediately closed

* Fix menu items triggering modal actions

* Add Tab trapping inside dropdown menu

* Give focus back to last focused element when status dropdown menu closes

app/javascript/mastodon/actions/modal.js

@@ -9,8 +9,9 @@ export function openModal(type, props) {
   };
 };
 
-export function closeModal() {
+export function closeModal(type) {
   return {
     type: MODAL_CLOSE,
+    modalType: type,
   };
 };