does g support svg mask API

- [x] I have searched the [issues](https://github.com/antvis/g/issues) of this repository and believe that this is not a duplicate.

### What problem does this feature solve?
```

```

does g support svg mask API？I only found clipPath API in document and source code。

### What does the proposed API look like?
```
const rect = new Rect({
style: {
mask: maskPath,
x: 0,
y: 0,
width: 82,
height: 42,
}
})
```