Issue #2004506 by cam8001, plach: Move standard_country_list() to Drupal\Core\Locale\Country.

core/core.services.yml

core/includes/install.core.inc

core/includes/standard.inc

core/lib/Drupal/Core/Locale/CountryManager.php

core/lib/Drupal/Core/Locale/CountryManagerInterface.php

core/modules/system/lib/Drupal/system/Form/RegionalForm.php

core/modules/system/system.api.php

core/modules/system/system.module

core/scripts/update-iso-3166.sh