This lets us accept spec-compliant CBOR tag for message envelopes.

This also includes a change in v8-inspector-session-impl.cc that
relaxes an envelope check to allow spec-compliant envelopes.

Change-Id: Id77c1e0fc4b62d78e8580f81ef38d50e3eb54a1d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3662540Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Andrey Kosyakov <caseq@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80761}