[EVENTS] Change FormatNoteList do separate in and out arguments

This is necessary due to some weird problem which I wasn't able to figure out (but which doesn't matter)
that somehow causes the event to be called twice during testing, and thus the function was exploding

tests/Core/ControllerTest.php

@@ -0,0 +1,43 @@
+<?php
+
+// {{{ License
+
+// This file is part of GNU social - https://www.gnu.org/software/social
+//
+// GNU social 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.
+//
+// GNU social 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 GNU social.  If not, see <http://www.gnu.org/licenses/>.
+
+// }}}
+
+namespace App\Tests\Core;
+
+use App\Util\GNUsocialTestCase;
+use Jchook\AssertThrows\AssertThrows;
+
+class ControllerTest extends GNUsocialTestCase
+{
+    use AssertThrows;
+
+    public function testJSONRequest()
+    {
+        // `server` will populate $_SERVER on the other side
+        $client = static::createClient(options: [], server: ['HTTP_ACCEPT' => 'application/json']);
+        $client->request('GET', '/main/all');
+        $this->assertResponseIsSuccessful();
+        $response = $client->getResponse();
+        static::assertTrue($response->headers->contains('Content-Type', 'application/json'));
+        static::assertJson($response->getContent());
+        $json = json_decode($response->getContent(), associative: true);
+        dd($json);
+    }
+}