PSR2ModifierVisibilityStaticOrder mangles nullable type declarations in function parameters

e.g.,

`PSR2ModifierVisibilityStaticOrder` disabled:

```php
class Foo {
    static public function bar(?string $baz) {
        noop();
    }
}

function foo(?string $bar): void {
    noop();
}
```

`PSR2ModifierVisibilityStaticOrder` enabled:

```php
class Foo {
    public static function bar(?string $baz) {
        noop();
    }
}

function foo(string ? $bar): void {
    noop();
}
```