Issue #3055193 by catch, martin107, jungle, mikelutz, longwave, andypost,...

Issue #3055193 by catch, martin107, jungle, mikelutz, longwave, andypost, alexpott, mondrake, tim.plunkett, larowlan: [Symfony 5] The "Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesser" class is deprecated since Symfony 4.3, use "Symfony\Component\Mime\MimeTypes" instead