[wire][client] Make the object tables thread-safe.

- This is only necessary to handle the always spontaneous logging and
  uncaptured error callbacks. The lookup table for the handles of
  these objects on the client can race since callbacks can be called
  from multiple threads, i.e. the main thread can be creating a new
  object, while the callback thread could be trying to lookup another
  existing one.

Bug: 501096128
Change-Id: I8d6da30d7cfb416507b458d8c39086a35532684f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/302499
Auto-Submit: Loko Kung <lokokung@google.com>
Commit-Queue: Loko Kung <lokokung@google.com>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>