Revert "[skif] Add FilterResult::Builder and update SkMergeImageFilter to use it"

This reverts commit 5274dd0eed5219610ba9d97bcc8675267933765c.

Reason for revert: suppression for Merge impl was landed, but it didn't cover a change from src to src-over for FilterResult drawing, which could produce the layout test failures.

Original change's description:
> [skif] Add FilterResult::Builder and update SkMergeImageFilter to use it
>
> Bug: skia:9282
> Bug: b/263133201
> Bug: b/263133780
> Change-Id: I568eb34255309d18c9699443727a5f8661d4cd39
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/697478
> Commit-Queue: Michael Ludwig <michaelludwig@google.com>
> Reviewed-by: Brian Osman <brianosman@google.com>

Bug: skia:9282
Bug: b/263133201
Bug: b/263133780
Change-Id: I814938728df2b2ca9b2772566093b1f1174163f7
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/701518
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
3 files changed