Add message on every action

Problem/Motivation

No message when action is performed after adding or removing the field value.

Steps to reproduce

Proposed resolution

 $field_name_array = explode("_",$field);
        $field_name = ucfirst(end($field_name_array));
        if (isset($change_method[$field])) {
          switch ($change_method[$field]) {
            case 'new':
              $current_value = $entity->{$field}->getValue();
              $value = array_unique(array_merge($current_value, $value), SORT_REGULAR);
              \Drupal::messenger()->addStatus("The specified users have been granted $field_name access to the specified pages.");
              break;

Remaining tasks

User interface changes

API changes

Data model changes