Add a special logging tag to uncaught handler exceptions

[masad-frost]

Why

We want to pipe uncaught errors in handlers to Sentry, we think it's ok to do that via the logger as opposed to having a special error callback.

What changed

• Add tag uncaught-handler-error
• Include originalException in extras (for proper stack traces)
• Change extras in logs from unknown to an optional Record<string, unknown> (we're using it that way anyway, just makes it easier to handle)

Versioning

• Breaking protocol change
• Breaking ts/js API change

[Monkatraz]

lgtm