refactor(modules): extract castopod parts into a modules/ folder for a scalable HMVC structure

- create Admin, Analytics, Auth, Fediverse and Install modules in the root modules/ folder
- rename
ActivityPub to Fediverse

modules/Fediverse/Controllers/SchedulerController.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright  2021 Podlibre
+ * @license    https://www.gnu.org/licenses/agpl-3.0.en.html AGPL3
+ * @link       https://castopod.org/
+ */
+
+namespace Modules\Fediverse\Controllers;
+
+use CodeIgniter\Controller;
+
+class SchedulerController extends Controller
+{
+    /**
+     * @var string[]
+     */
+    protected $helpers = ['activitypub'];
+
+    public function activity(): void
+    {
+        // retrieve scheduled activities from database
+        $scheduledActivities = model('ActivityModel')
+            ->getScheduledActivities();
+
+        // Send activity to all followers
+        foreach ($scheduledActivities as $scheduledActivity) {
+            // send activity to all actor followers
+            send_activity_to_followers(
+                $scheduledActivity->actor,
+                json_encode($scheduledActivity->payload, JSON_THROW_ON_ERROR),
+            );
+
+            // set activity post to delivered
+            model('ActivityModel')
+                ->update($scheduledActivity->id, [
+                    'task_status' => 'delivered',
+                ]);
+        }
+    }
+}