Issue #3245553 by quietone, danflanagan8: Fix migration of localized D6 menu links

...ontent_translation/migrations/d6_menu_links_localized.yml

core/modules/menu_link_content/migrations/d6_menu_links.yml

.../menu_link_content/src/Plugin/migrate/source/MenuLink.php

...ts/src/Kernel/Migrate/d6/MigrateMenuLinkLocalizedTest.php

...ntent/tests/src/Kernel/Migrate/d6/MigrateMenuLinkTest.php

.../src/Kernel/Migrate/d6/MigrateMenuLinkTranslationTest.php