Implement elliptical Arc support in path SVG shape

Add support for `A` (elliptical Arc) in path SVG shape, for example:

```
<path d="M35 25 L115 25 A 10 20 0 0 1 125 45 L 125 105 A 10 20 0 0 1 115 125 L 35 125 A 10 20 0 0 1 25 105 L 25 45 A 10 20 0 0 1 35 25" fill="red"/>
```

This will fix shapes-intro-02-f-manual, struct-image-18-f-manual, paths-data-19-f-manual tests from SVG 1.1 Test Suite.