Issue #2071481 by tim.plunkett: Modernize user.module forms.

core/modules/user/lib/Drupal/user/AccountFormController.php

core/modules/user/lib/Drupal/user/AccountSettingsForm.php

core/modules/user/lib/Drupal/user/Form/UserLoginForm.php

core/modules/user/lib/Drupal/user/Form/UserPasswordForm.php

...modules/user/lib/Drupal/user/Form/UserPermissionsForm.php

core/modules/user/lib/Drupal/user/Form/UserRoleDelete.php

core/modules/user/lib/Drupal/user/ProfileFormController.php

core/modules/user/lib/Drupal/user/RegisterFormController.php

core/modules/user/lib/Drupal/user/RoleFormController.php