Separate creating Wasm translations from reporting them to an agent.
This is done in order to support multiple connected sessions.

Previously connecting more than one agent would fail assertion in debug
mode and overwrite translation objects over and over
(and potentially do something worse) in release mode.

Bug: v8:9725
Change-Id: I13fde5ebf6e64e7268eb6870f9c21ac9a5bed81e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1807273Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Ingvar Stepanyan <rreverser@google.com>
Cr-Commit-Position: refs/heads/master@{#63867}