n-api: define ECMAScript-compliant accessors on napi_define_class

PR-URL: https://github.com/nodejs/node/pull/27851
Fixes: https://github.com/nodejs/node/issues/26551
Fixes: https://github.com/nodejs/node-addon-api/issues/485


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>