fix: #3625171 MenuLinkContent::getUrlObject() does not resolve the translated link field on multilingual sites

fix: #3625171 MenuLinkContent::getUrlObject() does not resolve the translated link field on multilingual sites

Closes #3625171

Converts the patch from the issue into an MR. On multilingual sites, MenuLinkContent::getUrlObject() now builds the URL from the link field of the entity translation for the current language context (the same approach getTitle() and getDescription() already use). The description is still added as the title attribute when $title_attribute is TRUE, as in MenuLinkBase::getUrlObject(). Non-multilingual sites keep the existing behavior. Still needs test coverage for the multilingual case.