[WebSignOut] Update IdentityManager notification error to contain the token operation source

The source defaults to
signin_metrics::SourceForRefreshTokenOperation:kUnknown if not set.
It also currently means that if no changes happened to the token
e.g. token is invalid due to server changes.
b/331626628 tracks the changes to create a new value to differentiate
the default, with not changing the token.

Bug: b/331368058
Change-Id: I0338279858428ffcfb5b5affef9299f8ca4651ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5388448


Reviewed-by: Florian Leimgruber <fleimgruber@google.com>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: Ryan Sultanem <rsult@google.com>
Cr-Commit-Position: refs/heads/main@{#1279090}