[svg] Add support for mask color-interpolation

https://www.w3.org/TR/SVG11/painting.html#ColorInterpolationProperty

Bug: skia:10842
Change-Id: I3e97577ee257c9afe64d924c768c85badbfab07d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/354220
Commit-Queue: Florin Malita <fmalita@google.com>
Reviewed-by: Tyler Denniston <tdenniston@google.com>
6 files changed