Implement image previewing

I have tested this with png and jpeg/jpg which both work but most other image types should work as well.
![image](/attachments/25318577-d48c-4902-93b3-9adbb8b954e7)

Co-authored-by: Jan Klattenhoff <j.klattenhoff@neusta.de>
Reviewed-on: sites/file-explorer#12
Co-authored-by: jank1619 <jan@kjan.email>
Co-committed-by: jank1619 <jan@kjan.email>

src/Controller/ServeFileController.php

@@ -0,0 +1,28 @@
+<?php declare(strict_types=1);
+
+namespace App\Controller;
+
+use App\Service\FileSystemService;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\BinaryFileResponse;
+use Symfony\Component\HttpFoundation\ResponseHeaderBag;
+use Symfony\Component\Routing\Attribute\Route;
+
+class ServeFileController extends AbstractController
+{
+    public function __construct(private FileSystemService $fileSystemService)
+    {
+    }
+
+    #[Route("/serve/{filePath}", name: "serve_file")]
+    public function __invoke(string $filePath): BinaryFileResponse
+    {
+        $file = $this->fileSystemService->getFile($filePath);
+        $path = $file->getPath() . '/' . $file->getName();
+
+        $response = new BinaryFileResponse($path);
+        $response->setContentDisposition(ResponseHeaderBag::DISPOSITION_ATTACHMENT, $file->getName());
+
+        return $response;
+    }
+}