[svg] Add svg_tool

A simple svg -> png converter, to demonstrate basic API usage.

TBR=
Change-Id: I34417c437b91e97811f5db512a9e79aa5cc099b8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/325336
Reviewed-by: Florin Malita <fmalita@google.com>
Commit-Queue: Florin Malita <fmalita@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
2 files changed