resolve magento 2.3 update conflicts

Author: klimart

lib/internal/Magento/Framework/GraphQl/Config.php

@@ -10,6 +10,7 @@
 use Magento\Framework\Config\DataInterface;
 use Magento\Framework\GraphQl\Config\ConfigElementFactoryInterface;
 use Magento\Framework\GraphQl\Config\ConfigElementInterface;
+use Magento\Framework\GraphQl\Query\Fields as QueryFields;
 
 /**
  * Provides access to typing information for a configured GraphQL schema.