improvements-2.x-dev/src/Plugin/Field/FieldFormatter/TextWithoutEscapingFormatter.php

<?php

namespace Drupal\improvements\Plugin\Field\FieldFormatter;

use Drupal\Component\Utility\Xss;
use Drupal\Core\Field\Attribute\FieldFormatter;
use Drupal\Core\Field\FieldItemInterface;
use Drupal\Core\Field\Plugin\Field\FieldFormatter\StringFormatter;
use Drupal\Core\StringTranslation\TranslatableMarkup;

#[FieldFormatter(
  id: 'text_without_escaping',
  label: new TranslatableMarkup('Text without escaping'),
  field_types: ['string'],
)]
class TextWithoutEscapingFormatter extends StringFormatter {

  /**
   * {@inheritdoc}
   */
  protected function viewValue(FieldItemInterface $item): array {
    return [
      '#markup' => Xss::filterAdmin($item->value),
    ];
  }

}