Refactor workflow classes and forms

- the workflow controller add a context to each transition;
- the state of the entity workflow is applyied using a dedicated marking store
- the method EntityWorkflow::step use the context to associate the new step with the future destination user, cc users and email. This makes the step consistent at every step.
- this allow to remove some logic which was processed in eventSubscribers,
- as counterpart, each workflow must specify a dedicated marking_store:

```yaml
framework:
    workflows:
        vendee_internal:
            # ...
            marking_store:
                service: Chill\MainBundle\Workflow\EntityWorkflowMarkingStore
```

src/Bundle/ChillMainBundle/Workflow/EntityWorkflowMarkingStore.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\MainBundle\Workflow;
+
+use Chill\MainBundle\Entity\Workflow\EntityWorkflow;
+use Symfony\Component\Workflow\Marking;
+use Symfony\Component\Workflow\MarkingStore\MarkingStoreInterface;
+
+final readonly class EntityWorkflowMarkingStore implements MarkingStoreInterface
+{
+    public function getMarking(object $subject): Marking
+    {
+        if (!$subject instanceof EntityWorkflow) {
+            throw new \UnexpectedValueException('Expected instance of EntityWorkflow');
+        }
+        $step = $subject->getCurrentStep();
+
+        return new Marking([$step->getCurrentStep() => 1]);
+    }
+
+    public function setMarking(object $subject, Marking $marking, array $context = []): void
+    {
+        if (!$subject instanceof EntityWorkflow) {
+            throw new \UnexpectedValueException('Expected instance of EntityWorkflow');
+        }
+
+        $places = $marking->getPlaces();
+        if (1 < count($places)) {
+            throw new \LogicException('Expected maximum one place');
+        }
+        $next = array_keys($places)[0];
+
+        $transitionDTO = $context['context'] ?? null;
+        if (!$transitionDTO instanceof WorkflowTransitionContextDTO) {
+            throw new \UnexpectedValueException(sprintf('Expected instance of %s', WorkflowTransitionContextDTO::class));
+        }
+
+        $subject->setStep($next, $transitionDTO);
+    }
+}