[inspector] Use ephemeron table for exception metadata

EphemeronHashTable does not trigger interrupts when accessed
(as opposed to calling the WeakMapGet builtin), so it avoids
the use-after-free problem when reading exception metadata
triggers session disconnect while holding a reference
to the session.

Bug: chromium:1241860
Change-Id: I29264b04b8daf682e7c33a97faedf50e323d57c4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3158326


Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76864}