add filters, update api, update api docs

backend/modules/questionnaire/views/user-response/index.php

@@ -20,6 +20,13 @@ $this->params['breadcrumbs'][] = $this->title;
         <?= Html::a('Новый ответ пользователя', ['create'], ['class' => 'btn btn-success']) ?>
     </p>
 
+ <?php
+ //echo $this->render('_search_by_questionnaire', [
+//        'model' => $searchModel,
+//    ])
+ ?>
+
+
     <?= GridView::widget([
         'dataProvider' => $dataProvider,
         'filterModel' => $searchModel,