This change is made to comply with the new Symfony standards and to avoid deprecation warnings for future versions. The update touches various functionalities, including retrieving EntityManagerInterface instance and various service classes within the test files.
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`.
