[Filesystem] fixed minor bugs

| Q             | A
| ------------- | ---
| Fixed tickets | fixed minor bugs
| License       | MIT

In the options, expected boolean value. It makes no sense to check for the existence of options, and then check the value.

```php
(isset($options['delete']) && $options['delete'])) === !empty($options['delete'])
```
Method `Filesystem::copy()` expects third argument boolean value. In the current implementation, there can get the value of another type. Now this is not terrible, but it can cause problems in the future.