Menu link URL should be translatable

I've created a MR rerolling the patch from #33 to the latest Drupal 11.x release. I'm attaching also a static patch to apply safely from composer

Believe this feature will need test coverage.

Have not reviewed

Issue:
When link field is made untranslatable for a particular menu type from /admin/config/regional/content-language, I get the following error:

Error: Call to undefined method Drupal\Core\Field\Entity\BaseFieldOverride::setItemDefinition() in Drupal\menu_link_content\Entity\MenuLinkContent->setTranslationConstraints() (line 444 of /var/www/html/docroot/core/modules/menu_link_content/src/Entity/MenuLinkContent.php).

While debugging, i found that when link field is translatable, the $item_definition object is instance of class Drupal\Core\Field\BaseFieldDefinition and when non-translatable, the object is instance of class Drupal\Core\Field\Entity\BaseFieldOverride where `setItemDefinition` method is not defined.

Fix for issue described in #40