Padding and BorderBrush of the gallery control do not work

Padding and BorderBrush of the gallery control do not work.

```
<fluent:Gallery Grid.Row="0"
                BorderBrush="Red"
                BorderThickness="1"
                Padding="0"
                ...
```

I will create a pull request for this issue later.

---
### Environment

- Fluent.Ribbon __v10.0.4__
- Windows __11__
- .NET __7.0__
