Merge pull request #24360 from owncloud/cleanup_non_psr4

lib/private/NaturalSort_DefaultCollator.php

lib/private/legacy/api.php

lib/private/legacy/app.php

lib/private/legacy/archive.php

lib/private/legacy/db.php

lib/private/legacy/defaults.php

lib/private/legacy/eventsource.php

lib/private/legacy/filechunking.php

lib/private/legacy/files.php

lib/private/legacy/group.php

lib/private/legacy/helper.php

lib/private/legacy/hook.php

lib/private/legacy/image.php

lib/private/legacy/installer.php

lib/private/legacy/json.php

lib/private/legacy/ocs.php

lib/private/legacy/response.php

lib/private/legacy/template.php

lib/private/legacy/user.php

lib/private/legacy/util.php