MDL-30646 default qbank sort should only use visible columns.

mod/quiz/editlib.php

@@ -1106,6 +1106,10 @@ class quiz_question_bank_view extends question_bank_view {
                 'editaction', 'previewaction');
     }
 
+    protected function default_sort() {
+        return array('qtype' => 1, 'questionnametext' => 1);
+    }
+
     /**
      * Let the question bank display know whether the quiz has been attempted,
      * hence whether some bits of UI, like the add this question to the quiz icon,