Issue #3341586: Allow to get the label from the field_display_label module

src/Plugin/Field/FieldFormatter/PatternOneForAllFormatter.php

@@ -180,6 +180,11 @@ class PatternOneForAllFormatter extends FieldWrapperBase implements ContainerFac
         if ($field['source'] == '_label') {
           $fields[$field['destination']][] = $items->getFieldDefinition()->getLabel();
         }
+        elseif ($field['source'] == '_field_display_label') {
+          if ($this->moduleHandler->moduleExists('field_display_label')) {
+            $fields[$field['destination']][] = $items->getFieldDefinition()->getThirdPartySetting('field_display_label', 'display_label');
+          }
+        }
         elseif ($field['source'] == '_formatted') {
           $field_output = $this->getFieldOutput($items, $langcode);
           // Take the element children from the field output and return them.