Issue #3385834 by vbouchet, joachim: MenuUiNodeTest should use API to set up language

namespace Drupal\Tests\menu_ui\Functional;

use Drupal\Core\Language\LanguageInterface;

use Drupal\language\Entity\ConfigurableLanguage;

use Drupal\language\Entity\ContentLanguageSettings;

use Drupal\menu_link_content\Entity\MenuLinkContent;

use Drupal\node\Entity\Node;

use Drupal\node\Entity\NodeType;

    $config->set('url.prefixes.' . $langcodes[0], $langcodes[0]);

    $config->save();

    $this->rebuildContainer();

    $languages = [];

    foreach ($langcodes as $langcode) {

      $languages[$langcode] = ConfigurableLanguage::load($langcode);

    }

    // Use a UI form submission to make the node type and menu link content entity translatable.

    $this->drupalLogout();

    $this->drupalLogin($this->rootUser);

    $edit = [

      'entity_types[node]' => TRUE,

      'entity_types[menu_link_content]' => TRUE,

      'settings[node][page][settings][language][language_alterable]' => TRUE,

      'settings[node][page][translatable]' => TRUE,

      'settings[node][page][fields][title]' => TRUE,

      'settings[menu_link_content][menu_link_content][translatable]' => TRUE,

    ];

    $this->drupalGet('admin/config/regional/content-language');

    $this->submitForm($edit, 'Save configuration');

    // Enable translation for page.

    $config = ContentLanguageSettings::loadByEntityTypeBundle('node', 'page');

    $config->setDefaultLangcode(LanguageInterface::LANGCODE_SITE_DEFAULT);

    $config->setLanguageAlterable(TRUE);

    $config->save();

    // Log out and back in as normal user.

    $this->drupalLogout();

    $this->drupalLogin($this->editor);

    $content_translation_manager = $this->container->get('content_translation.manager');

    $content_translation_manager->setEnabled('node', 'page', TRUE);

    $content_translation_manager->setBundleTranslationSettings('node', 'page', [

      'untranslatable_fields_hide' => FALSE,

    ]);

    // Enable translation for menu_link_content.

    $config = ContentLanguageSettings::loadByEntityTypeBundle('menu_link_content', 'menu_link_content');

    $config->setDefaultLangcode(LanguageInterface::LANGCODE_SITE_DEFAULT);

    $config->setLanguageAlterable(TRUE);

    $config->save();

    $content_translation_manager = $this->container->get('content_translation.manager');

    $content_translation_manager->setEnabled('menu_link_content', 'menu_link_content', TRUE);

    $content_translation_manager->setBundleTranslationSettings('menu_link_content', 'menu_link_content', [

      'untranslatable_fields_hide' => FALSE,

    ]);

    $this->rebuildContainer();

    // Create a node.

    $node_title = $this->randomMachineName(8);