message: fix: move clear all notifications entry to bottom
  If there are more than ~ 25 unread notifications the clear
  all menu item is not reachable, because the menu is not
  scrollable.
diff: @@ -195,7 +195,7 @@ export default class Roster {
  noticeElement.attr('title', notice.getDescription());
  noticeElement.attr('data-notice-id', notice.getId());
  noticeElement.attr('data-manager-id', manager.getId());
  - noticeListElement.append(noticeElement);
  + noticeListElement.prepend(noticeElement);
  let numberOfNotices = noticeListElement.find('li').not('.jsxc-js-delete-all').length;
  $('.jsxc-js-notice-menu .jsxc-menu__button').text(numberOfNotices);
  @@ -204,7 +204,7 @@ export default class Roster {
  let deleteAllElement = $('<li>');
  deleteAllElement.addClass('jsxc-js-delete-all jsxc-menu__item--danger jsxc-icon--delete');
  deleteAllElement.text(Translation.t('Close_all'));
  - deleteAllElement.prependTo(noticeListElement);
  + deleteAllElement.appendTo(noticeListElement);
  deleteAllElement.click((ev) => {
  ev.stopPropagation();
  