[svg] Plumb a ResourceProvider

... for image loading.

Update the SVG tools to pass local/FS resource providers.

Change-Id: I2c0e446047da87f177fde0f23b7ea1f0a856e808
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/359996
Commit-Queue: Florin Malita <fmalita@google.com>
Reviewed-by: Tyler Denniston <tdenniston@google.com>
10 files changed