Trim PersonIdentifier values during denormalization, implement RequiredIdentifierConstraint and validator, and add tests for empty value validation.

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

@@ -0,0 +1,27 @@
+<?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 Symfony\Component\Validator\Constraint;
+
+/**
+ * Test that the required constraints are present.
+ */
+class RequiredIdentifierConstraint extends Constraint
+{
+    public string $message = 'This identifier must be set';
+
+    public function getTargets(): string
+    {
+        return self::PROPERTY_CONSTRAINT;
+    }
+}