Double decode numeric reference

```
test("xmlbuilder2 decodes escaped numeric character references when parsing XML text", () => {
    const doc = create({ skipWhitespaceOnlyText: false }, "<wrapper>&amp;#128512;</wrapper>");
    const textNode = doc.node.documentElement.firstChild;
    assert.equal(textNode.nodeValue, "&#128512;");
});
```
The test is failed. and the actual output: '😀'

Is this a bug?