Revert of [keys] Simplify KeyAccumulator (patchset #15 id:280001 of https://codereview.chromium.org/1995263002/ )

Reason for revert:
https://build.chromium.org/p/client.v8/builders/V8%20Mac%20GC%20Stress/builds/6248

Original issue's description:
> [keys] Simplify KeyAccumulator
>
> - Use KeyAccumulator::GetKeys directly instead of JSReceiver::GetKeys
> - Revert KeyAccumulator to single OrderedHashSet implementation.
> - Convert the OrderedHashSet in-place to a FixedArray
> - IndexedInterceptor indices are no longer combined and sorted with the object indices
>
> BUG=
>
> Committed: https://crrev.com/d3324df017046bcde247a5aef6d1b59bfae5908f
> Cr-Commit-Position: refs/heads/master@{#36485}

TBR=jkummerow@chromium.org,verwaest@chromium.org,cbruni@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review-Url: https://codereview.chromium.org/2010593002
Cr-Commit-Position: refs/heads/master@{#36486}