[fuzz] Add a fuzzer for COLRv1 rendering

Skia side change before adding this to build script and adding corpus to
the oss-fuzz project.

In the initial Chrome COLRv1 launch review it was suggested to add a
fuzzer for the Skia side rendering code, which this change begins to set
up.

Bug: skia:13675
Change-Id: I212843af793a58bf81cdd179636cdcb3c50a312d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/571934
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Dominik Röttsches <drott@google.com>
3 files changed