FEATURE: Redesigned bookmark modal and menu (#23071)

Adds the new quick menu for bookmarking. When you bookmark
a post (chat message behaviour will come later) we show this new quick
menu and bookmark the item straight away.

You can then choose a reminder quick option, or choose Custom... to open
the old modal. If you click on an existing bookmark, we show the same quick menu
but with Edit and Delete options.

A later PR will introduce a new bookmark modal, but for now we
are using the old modal for Edit and Custom... options.

spec/system/page_objects/components/bookmark_menu.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module PageObjects
+  module Components
+    class BookmarkMenu < PageObjects::Components::Base
+      def click_menu_option(option_id)
+        find(".bookmark-menu__row[data-menu-option-id='#{option_id}']").click
+      end
+
+      def open?
+        has_css?(".bookmark-menu__body")
+      end
+    end
+  end
+end