Fix Fee name not showing (#602)

Fix Fee name not showing on the order when using the createOrder mutation.

Author: scottyzen

includes/data/mutation/class-order-mutation.php

@@ -232,7 +232,7 @@ protected static function get_order_item_keys( $type ) {
 
 			case 'fee':
 				return array(
-					'name'      => 'order_item_name',
+					'name'      => 'name',
 					'taxClass'  => 'tax_class',
 					'taxStatus' => 'tax_status',
 				);