Feature: [docgen] generate documents in an async queue

The documents are now generated in a queue, using symfony messenger. This queue should be configured:

```yaml
# app/config/messenger.yaml
framework:
    messenger:
        # reset services after consuming messages
        # reset_on_message: true

        failure_transport: failed

        transports:
            # https://symfony.com/doc/current/messenger.html#transport-configuration
            async: '%env(MESSENGER_TRANSPORT_DSN)%'
            priority:
                dsn: '%env(MESSENGER_TRANSPORT_DSN)%'
            failed: 'doctrine://default?queue_name=failed'

        routing:
            # ... other messages
            'Chill\DocGeneratorBundle\Service\Messenger\RequestGenerationMessage': priority
```

`StoredObject`s now have additionnal properties:

* status (pending, failure, ready (by default) ), which explain if the document is generated;
* a generationTrialCounter, which is incremented on each generation trial, which prevent each generation more than 5 times;

The generator computation is moved from the `DocGenTemplateController` to a `Generator` (implementing `GeneratorInterface`. 

There are new methods to `Context` which allow to normalize/denormalize context data to/from a messenger's `Message`.

src/Bundle/ChillPersonBundle/Service/DocGenerator/AccompanyingPeriodWorkContext.php

@@ -11,6 +11,7 @@ declare(strict_types=1);
 
 namespace Chill\PersonBundle\Service\DocGenerator;
 
+use Chill\DocGeneratorBundle\Context\DocGeneratorContextWithPublicFormInterface;
 use Chill\DocGeneratorBundle\Entity\DocGeneratorTemplate;
 use Chill\DocStoreBundle\Entity\StoredObject;
 use Chill\PersonBundle\Entity\AccompanyingPeriod\AccompanyingPeriodWork;
@@ -18,7 +19,13 @@ use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\Serializer\Normalizer\AbstractNormalizer;
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 
-class AccompanyingPeriodWorkContext
+/**
+ * Generate a context for an @link{AccompanyingPeriodWork}.
+ *
+ * Although there isn't any document associated to AccompanyingPeriodWork, this context
+ * is use by @link{AccompanyingPeriodWorkEvaluationContext}.
+ */
+class AccompanyingPeriodWorkContext implements DocGeneratorContextWithPublicFormInterface
 {
     private NormalizerInterface $normalizer;
 
@@ -109,8 +116,18 @@ class AccompanyingPeriodWorkContext
         return $this->periodContext->hasPublicForm($template, $entity);
     }
 
+    public function contextGenerationDataNormalize(DocGeneratorTemplate $template, $entity, array $data): array
+    {
+        return $this->periodContext->contextGenerationDataNormalize($template, $entity, $data);
+    }
+
+    public function contextGenerationDataDenormalize(DocGeneratorTemplate $template, $entity, array $data): array
+    {
+        return $this->periodContext->contextGenerationDataDenormalize($template, $entity, $data);
+    }
+
     public function storeGenerated(DocGeneratorTemplate $template, StoredObject $storedObject, object $entity, array $contextGenerationData): void
     {
-        // TODO: Implement storeGenerated() method.
+        // currently, no document associated with a AccompanyingPeriodWork
     }
 }