Field access & denominator are marking map item fields access as forbidden

Problem/Motivation

This module provides field access hook which is based upon property `denominator` to determine access rights.

The problem is that Drupal core Map - \Drupal\Core\Field\Plugin\Field\FieldType\MapItem field type have simple getter

  /**
   * {@inheritdoc}
   */
  public function __get($name) {
    if (!isset($this->values[$name])) {
      $this->values[$name] = [];
    }

    return $this->values[$name];
  }

Which in conjunction with webform_score_entity_field_access is going to mark any Map field type as forbidden.

  if (!$items || !$items[0] || is_null($items[0]->denominator)) {
    return AccessResult::neutral();
  }

  if (!$items[0]->denominator) {
    // No scoring is configured.
    return AccessResult::forbidden()->cachePerPermissions();
  }

Steps to reproduce

Proposed resolution

We should check by field type initiall, if is not fraction, that access is neutral

Remaining tasks

User interface changes

API changes

Data model changes