KeyedAccessStoreMode is used when creating store handlers to determine
which cases to handle (ex: handle cow, grow) and hence choose an
approriate builtin. It is also used to specify elements kind transitions
which is used when computing ic transitions. The store mode and the
transition mode are independent of each other and it would be cleaner to
use different enums to represent them. This also reduces the total number
of cases in each enum.

Change-Id: I96aeff7a765b312b8088e831776743c67c533bd9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1619751Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61729}