[css-backgrounds-4] Can you chain `border-area` and `text` in `background-clip`?

#9456 added `background-clip: border-area`.

I think it would be useful to support `background-clip: border-area text` in case you want your background to bleed through both the text and the border-area of an element.

The new syntax would then be:

```
<bg-clip> = <visual-box> | [ border-area || text ]
```

