feat(skia): bind to Skia's SVGDOM

[zbaylin]

This uses Skia's SVGDOM API to render SVGs onto Skia canvas's, which is exactly what we need for SVG rendering!

The basic process to get it working is:

• Create an SkStream of some sort from the SVG you want to render
  • You can either construct an SkMemoryStream from an SVG string in memory, or an SkFileStream from an SVG file
• Create an SVG with the stream
• Render it onto a canvas

The results are surprisingly good, considering the SVG API is marked as "experimental" in Skia: