Add a support for StageManager view on iPadOS 16

### Please answer the following questions for yourself before submitting an issue.

- [X] I am running the latest version
- [ ] I checked the documentation and found no answer
- [ ] I checked to make sure that this issue has not already been filed

### AdGuard VPN version

2.0.9(77)

### Operating mode

General

### Environment

```markdown
- OS:iPadOS 16.4.1
- Device and storage size: iPad Pro 5th gen. 12”
```

### Issue Details

When using Ad Guard VPN App on the iPadOS 16 ‘Stage Manager’ function with a narrower screen size among the multiple windows, you cannot disconnect the VPN temporarily. Because you cannot see the ADD/CANCEL button on the bottom of the App window.

Pic. One - Stage Manager mode
Pic. Two - Normal Window mode

### Expected Behavior

ADD/CANCEL button should be appeared on the App window while using the Stage Manager narrower screen.

### Screenshots

Screenshot 1:

### Additional Information

_No response_