[sksg] Consolidate geometry effects

Dash, trim, round, transform and upcoming offset have a lot in common.

Introduce a GeometryEffect base class to consolidate.

TBR=
Change-Id: Ib5556e6ebe416685c624d53ba8591e118aa4f0d6
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300496
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
15 files changed