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

addresses #869cut134

src/Model/NewsletterSubscriptionRequestResult.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Model;
+
+class NewsletterSubscriptionRequestResult
+{
+    public const STATE_SUBSCRIBED = 'subscribed';
+    public const STATE_PENDING_CONFIRMATION = 'pending_confirmation';
+    public const STATE_CONFIRMATION_REQUESTED = 'confirmation_requested';
+    public const LIST_STATE_PENDING = 'pending';
+    public const LIST_STATE_ALREADY_REGISTERED = 'already_registered';
+    public const LIST_STATE_SUCCESS = 'success';
+
+    /**
+     * @param list<int> $listIds
+     * @param array<int, string> $listStates
+     */
+    public function __construct(
+        public readonly string $email,
+        public readonly array $listIds,
+        public readonly string $state,
+        public readonly bool $confirmationRequested,
+        public readonly array $listStates = [],
+    ) {
+    }
+
+    public function stateForList(int $listId): string
+    {
+        return $this->listStates[$listId] ?? match ($this->state) {
+            self::STATE_SUBSCRIBED => self::LIST_STATE_SUCCESS,
+            default => self::LIST_STATE_PENDING,
+        };
+    }
+}