Remove blend and colorFilter sksl modules

This moves the functions for dealing with child effects into the public
module (where those types already live). With that change, blend and
colorFilter have no module-specific declarations.

Change-Id: I7665e68427ea4d8d1ed4d31afb658edb79bac5a4
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/443412
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
13 files changed