Add unique constraint for PersonIdentifier, implement UniqueIdentifierConstraint with validation logic, and include supporting tests

- Introduce `UniqueIdentifierConstraint` and its validator for ensuring identifier uniqueness.
- Add a database-level unique constraint on `PersonIdentifier` (`definition_id`, `value`).
- Implement repository method to fetch identifiers by definition and value.
- Include integration and unit tests for validation and repository functionality.
- Update `Person` entity with `Assert\Valid` annotation for `identifiers`.

src/Bundle/ChillPersonBundle/PersonIdentifier/Validator/UniqueIdentifierConstraintValidator.php

@@ -0,0 +1,50 @@
+<?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\PersonBundle\PersonIdentifier\Validator;
+
+use Chill\PersonBundle\Entity\Identifier\PersonIdentifier;
+use Chill\PersonBundle\Repository\Identifier\PersonIdentifierRepository;
+use Chill\PersonBundle\Templating\Entity\PersonRenderInterface;
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+use Symfony\Component\Validator\Exception\UnexpectedTypeException;
+use Symfony\Component\Validator\Exception\UnexpectedValueException;
+
+class UniqueIdentifierConstraintValidator extends ConstraintValidator
+{
+    public function __construct(
+        private readonly PersonIdentifierRepository $personIdentifierRepository,
+        private readonly PersonRenderInterface $personRender,
+    ) {}
+
+    public function validate($value, Constraint $constraint): void
+    {
+        if (!$constraint instanceof UniqueIdentifierConstraint) {
+            throw new UnexpectedTypeException($constraint, UniqueIdentifierConstraint::class);
+        }
+
+        if (!$value instanceof PersonIdentifier) {
+            throw new UnexpectedValueException($value, PersonIdentifier::class);
+        }
+
+        $identifiers = $this->personIdentifierRepository->findByDefinitionAndValue($value->getDefinition(), $value->getValue());
+
+        if (count($identifiers) > 0) {
+            $persons = array_map(fn (PersonIdentifier $idf): string => $this->personRender->renderString($idf->getPerson(), []), $identifiers);
+
+            $this->context->buildViolation($constraint->message)
+                ->setParameter('{{ persons }}', implode(', ', $persons))
+                ->setParameter('definition_id', (string) $value->getDefinition()->getId())
+                ->addViolation();
+        }
+    }
+}