Update Signature App.vue to use a converted pdf

Introduced a new helper ts function to download documents as PDFs and integrated with the existing workflow. Enhanced `PDFSignatureZoneAvailable` to implement `LocaleAwareInterface` for better locale management and added PDF conversion handling for non-PDF documents. Updated App.vue to use the new PDF download method.

src/Bundle/ChillDocStoreBundle/Tests/Service/Signature/PDFSignatureZoneAvailableTest.php

@@ -22,6 +22,7 @@ use Chill\MainBundle\Entity\Workflow\EntityWorkflowSignatureStateEnum;
 use Chill\MainBundle\Workflow\EntityWorkflowManager;
 use Chill\MainBundle\Workflow\WorkflowTransitionContextDTO;
 use Chill\PersonBundle\Entity\Person;
+use Chill\WopiBundle\Service\WopiConverter;
 use PHPUnit\Framework\TestCase;
 use Prophecy\PhpUnit\ProphecyTrait;
 use Symfony\Component\Clock\MockClock;
@@ -65,6 +66,7 @@ class PDFSignatureZoneAvailableTest extends TestCase
             $entityWorkflowManager->reveal(),
             $parser->reveal(),
             $storedObjectManager->reveal(),
+            $this->prophesize(WopiConverter::class)->reveal(),
         );
 
         $actual = $filter->getAvailableSignatureZones($entityWorkflow);