feat: MailJet list handling with DOI, webhook receiver and API endpoint

addresses #869cut134

src/Model/NewsletterSubscriptionRequest.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Model;
+
+use Symfony\Component\Validator\Constraints as Assert;
+
+class NewsletterSubscriptionRequest
+{
+    #[Assert\NotBlank]
+    #[Assert\Email(mode: 'strict')]
+    public ?string $email = null;
+
+    #[Assert\Length(max: 255)]
+    public ?string $firstName = null;
+
+    #[Assert\Length(max: 255)]
+    public ?string $lastName = null;
+
+    /**
+     * @var list<int>
+     */
+    #[Assert\NotNull]
+    #[Assert\Type('array')]
+    #[Assert\Count(min: 1)]
+    #[Assert\All([
+        new Assert\Type('integer'),
+        new Assert\Positive(),
+    ])]
+    public array $listIds = [];
+}