n-api: add napi_fatal_exception

Add function to trigger and uncaught exception.
Useful if an async callback throws an exception with
no way to recover.

PR-URL: https://github.com/nodejs/node/pull/19337


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>