Port the WebformElementValidationPattern type to GraphQL 4.

Closes #3439408

src/Plugin/GraphQL/DataProducer/WebformElementProperty.php

@@ -31,10 +31,6 @@ use Symfony\Component\String\UnicodeString;
  *     "type" = @ContextDefinition("string",
  *       label = @Translation("The desired type."),
  *       required = FALSE
- *     ),
- *     "default" = @ContextDefinition("string",
- *       label = @Translation("Default value"),
- *       required = FALSE
  *     )
  *   }
  * )
@@ -92,18 +88,16 @@ class WebformElementProperty extends DataProducerPluginBase implements Container
     // from PascalCase to snake_case.
     $property = (new UnicodeString($property))->snake()->toString();
 
-    // Try to get the value from the element directly.
+    // If this is an element with multiple values, inspect the first actual
+    // element instead of the wrapper which is a fieldset or container.
+    if ($element['#type'] === 'webform_multiple' && !empty($element['items'][0]['_item_'])) {
+      $element = $element['items'][0]['_item_'];
+    }
+
     $plugin = $this->elementManager->getElementInstance($element);
     $value = $plugin->getElementProperty($element, $property);
 
-    // If we didn't find the value and this is an element with multiple values,
-    // we are looking inside the wrapper. Try getting the value from the first
-    // actual element instead.
-    if ($value === NULL && $element['#type'] === 'webform_multiple' && !empty($element['items'][0]['_item_'])) {
-      $value = $plugin->getElementProperty($element['items'][0]['_item_'], $property);
-    }
-
-    // If it's still not there, fall back to the "decoded" values. This is the
+    // If we didn't find a value, fall back to the "decoded" values. This is the
     // case for the "#description" field, which Webform removes from the
     // element.
     // @todo Check if this is actually necessary.