serializer on accompanying course

Two new routes:

* `GET /{_locale}/person/api/1.0/accompanying-course/{parcours_id}/show.json`: get a json representation for a course
* `POST /{_locale}/person/api/1.0/accompanying-course/{parcours_id}/participation.json`:
add a particitipation to course. Usage:

    `curl -v --cookie "PHPSESSID=fed98aa23e40cb36e630f84155aea3bb;" -X
POST --data '{ "id": 481 }'
http://localhost:8001/fr/person/api/1.0/accompanying-course/270/participation.json`

    Will add the person with id "481" to the course.

src/Bundle/ChillPersonBundle/Serializer/Normalizer/PersonNormalizer.php

@@ -0,0 +1,95 @@
+<?php
+/*
+ *
+ * Copyright (C) 2014-2021, Champs Libres Cooperative SCRLFS, <http://www.champs-libres.coop>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ *  License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+namespace Chill\PersonBundle\Serializer\Normalizer;
+
+use Chill\PersonBundle\Entity\Person;
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
+use Symfony\Component\Serializer\Normalizer\NormalizerAwareInterface;
+use Chill\PersonBundle\Repository\PersonRepository;
+use Symfony\Component\Serializer\Exception\RuntimeException;
+use Symfony\Component\Serializer\Exception\UnexpectedValueException;
+
+
+/**
+ * Serialize a Person entity
+ *
+ */
+class PersonNormalizer implements
+    NormalizerInterface,
+    NormalizerAwareInterface,
+    DenormalizerInterface
+{
+
+    protected NormalizerInterface $normalizer;
+
+    protected PersonRepository $repository;
+
+    public const GET_PERSON = 'get_person';
+
+    public function __construct(PersonRepository $repository)
+    {
+        $this->repository = $repository;
+    }
+
+    public function normalize($person, string $format = null, array $context = array())
+    {
+        /** @var Person $person */
+        return [
+            'id' => $person->getId(),
+            'firstName' => $person->getFirstName(),
+            'lastName' => $person->getLastName(),
+            'birthdate' => $person->getBirthdate(),
+            'center' => $this->normalizer->normalize($person->getCenter())
+        ];
+    }
+
+    public function denormalize($data, string $type, string $format = null, array $context = []): Person
+    {
+        if ($context[self::GET_PERSON] ?? true) {
+            $id = $data['id'] ?? null;
+            if (NULL === $id) {
+                throw new RuntimeException("missing id into person object");
+            }
+        }
+        /** var Person $person */
+        $person = $this->repository->findOneById($id);
+
+        if (NULL === $person) {
+            return UnexpectedValueException("person id not found");
+        }
+
+        return $person;
+    }
+
+    public function supportsNormalization($data, string $format = null): bool
+    {
+        return $data instanceof Person;
+    }
+
+    public function supportsDenormalization($data, string $type, ?string $format = NULL): bool
+    {
+        return Person::class === $type;
+    }
+
+    public function setNormalizer(NormalizerInterface $normalizer)
+    {
+        $this->normalizer = $normalizer;
+    }
+}