Issue #3368795: Use search form element instead of text

Closes #3368795

src/Element/SearchApiAutocomplete.php

@@ -4,7 +4,7 @@ namespace Drupal\search_api_autocomplete\Element;
 
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Render\BubbleableMetadata;
-use Drupal\Core\Render\Element\Textfield;
+use Drupal\Core\Render\Element\Search as Searchfield;
 use Drupal\search_api_autocomplete\Entity\Search;
 
 /**
@@ -12,7 +12,7 @@ use Drupal\search_api_autocomplete\Entity\Search;
  *
  * @FormElement("search_api_autocomplete")
  */
-class SearchApiAutocomplete extends Textfield {
+class SearchApiAutocomplete extends Searchfield {
 
   /**
    * {@inheritdoc}