Adding `functions.php` helper with `dd` function

[msmakouz]

What was changed

Added the ability to use the popular debugging function dd.

#[Route(route: '/', name: 'index')]
public function index(): string
{
    dd('Hello World');

    return $this->views->render('home');
}

Result:

[butschster]

Hey @msmakouz, we need to check if var-dumper works with buggregator when utilizing the spiral/dumper package. Let's look into this and ensure everything is set up correctly.