Issue 5160: Update advanced app to use bootstrap ActiveForm

apps/advanced/backend/views/site/login.php

 <?php
 use yii\helpers\Html;
-use yii\widgets\ActiveForm;
+use yii\bootstrap\ActiveForm;
 
 /* @var $this yii\web\View */
-/* @var $form yii\widgets\ActiveForm */
+/* @var $form yii\bootstrap\ActiveForm */
 /* @var $model \common\models\LoginForm */
 
 $this->title = 'Login';

apps/advanced/frontend/views/site/contact.php

 <?php
 use yii\helpers\Html;
-use yii\widgets\ActiveForm;
+use yii\bootstrap\ActiveForm;
 use yii\captcha\Captcha;
 
 /* @var $this yii\web\View */
-/* @var $form yii\widgets\ActiveForm */
+/* @var $form yii\bootstrap\ActiveForm */
 /* @var $model \frontend\models\ContactForm */
 
 $this->title = 'Contact';

apps/advanced/frontend/views/site/login.php

 <?php
 use yii\helpers\Html;
-use yii\widgets\ActiveForm;
+use yii\bootstrap\ActiveForm;
 
 /* @var $this yii\web\View */
-/* @var $form yii\widgets\ActiveForm */
+/* @var $form yii\bootstrap\ActiveForm */
 /* @var $model \common\models\LoginForm */
 
 $this->title = 'Login';

apps/advanced/frontend/views/site/requestPasswordResetToken.php

 <?php
 use yii\helpers\Html;
-use yii\widgets\ActiveForm;
+use yii\bootstrap\ActiveForm;
 
 /* @var $this yii\web\View */
-/* @var $form yii\widgets\ActiveForm */
+/* @var $form yii\bootstrap\ActiveForm */
 /* @var $model \frontend\models\PasswordResetRequestForm */
 
 $this->title = 'Request password reset';

apps/advanced/frontend/views/site/resetPassword.php

 <?php
 use yii\helpers\Html;
-use yii\widgets\ActiveForm;
+use yii\bootstrap\ActiveForm;
 
 /* @var $this yii\web\View */
-/* @var $form yii\widgets\ActiveForm */
+/* @var $form yii\bootstrap\ActiveForm */
 /* @var $model \frontend\models\ResetPasswordForm */
 
 $this->title = 'Reset password';

apps/advanced/frontend/views/site/signup.php

 <?php
 use yii\helpers\Html;
-use yii\widgets\ActiveForm;
+use yii\bootstrap\ActiveForm;
 
 /* @var $this yii\web\View */
-/* @var $form yii\widgets\ActiveForm */
+/* @var $form yii\bootstrap\ActiveForm */
 /* @var $model \frontend\models\SignupForm */
 
 $this->title = 'Signup';