We are often stepping multiple times without inspecting the state
in-between. Hence, the generated debug side table is often not being
used. Instead of always generating it, we can generate it lazily on
demand, which can avoid the need to generate it at all.

R=thibaudm@chromium.org

TEST=inspector/debugger/wasm-stepping

Bug: chromium:1172299
Change-Id: I9b9ff4485d65d720d23585856b3d672925460667
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2664446
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72484}