Move all ColorFilter subclasses to src/effects/colorfilters

Client CLs:
 - https://crrev.com/c/4577599
 - https://pdfium-review.googlesource.com/c/pdfium/+/107410

Of note, implementations of the Lerp, Luma, and Overdraw
filters were moved to SkRuntimeColorFilter.cpp due to the fact
they use SkSL. Alternate implementations (for no SkSL builds)
are in SkRuntimeColorFilter_none.cpp instead of being controlled
by #ifdefs.

Change-Id: I76430d48bcbfe6750c8d9504ba637b57b8419a46
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/705224
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
53 files changed