Add TransitionHasDestineeIfIsSentExternal validator

This commit introduces a new validator to ensure that transitions marked as 'sent' have a designated external recipient. It includes related tests for scenarios with and without recipients and covers integration with the workflow context.

src/Bundle/ChillMainBundle/Workflow/Validator/TransitionHasDestineeIfIsSentExternal.php

@@ -0,0 +1,31 @@
+<?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\Validator;
+
+use Symfony\Component\Validator\Constraint;
+
+/**
+ * Check that a transition does have at least one external if the 'to' is 'isSentExternal'.
+ */
+#[\Attribute]
+class TransitionHasDestineeIfIsSentExternal extends Constraint
+{
+    public $messageDestineeRequired = 'workflow.transition_has_destinee_if_sent_external';
+    public $messageDestineeNotNecessary = 'workflow.transition_destinee_not_necessary';
+    public $codeNoNecessaryDestinee = 'd78ea142-819d-11ef-a459-b7009a3e4caf';
+    public $codeDestineeUnauthorized = 'eb8051fc-8227-11ef-8c3b-7f2de85bdc5b';
+
+    public function getTargets(): string
+    {
+        return self::CLASS_CONSTRAINT;
+    }
+}