ENGCOM-4394: Refactoring the Form class #21474

 - Merge Pull Request #21474 from eduard13/magento2:2.3-develop-guest-form-integration-test
 - Merged commits:
   1. 9dc9829
   2. 37c10bc
   3. a146f50
   4. 96f6a61
   5. e4a1b8a
   6. 832bb70

Author: magento-engcom-team

app/code/Magento/Sales/Controller/Guest/Form.php

@@ -10,6 +10,7 @@
 
 use Magento\Customer\Model\Session as CustomerSession;
 use Magento\Framework\App\Action\Context;
+use Magento\Framework\App\Action\HttpGetActionInterface;
 use Magento\Framework\App\ObjectManager;
 use Magento\Framework\Controller\Result\Redirect;
 use Magento\Framework\View\Result\Page;
@@ -19,7 +20,7 @@
 /**
  * Class Form
  */
-class Form extends \Magento\Framework\App\Action\Action
+class Form extends \Magento\Framework\App\Action\Action implements HttpGetActionInterface
 {
     /**
      * @var PageFactory
@@ -71,4 +72,4 @@ public function execute()
 
         return $resultPage;
     }
-}
+}