[pp-1] Untranslated menu items are displayed in Superfish menus

Problem/Motivation

When menu items are created for a language (i.e English) and then other menu items are added for other languages (ie Spanish) not translated, the Superfish block displays all the untranslated menu items in all the languages. This is not an issue of Superfish itself but a consequence of the current situation with the core menu block (please check related issue), so it is inherited by Superfish.

Steps to reproduce

• Install Drupal with multiple languages and enable menu translation
• Create some content in different languages untranslated and add all of them to the main menu
• Display the main menu via superfish block
• Visit a page and the superfish block will render all the untranslated menu items regardless of current language

Expected result:

Only the translated menu items are displayed in the menu.

Proposed resolution

Modify the Superfish menu block plugin build() method to use the new "menu.language_tree_manipulator:filterLanguage" menu transformation callback introduced on 🐛 Untranslated menu items are displayed in menus Needs work