worker: make MessageEvent class more Web-compatible

PR-URL: https://github.com/nodejs/node/pull/35496
Fixes: https://github.com/nodejs/node/issues/35495


Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Shelley Vohr <codebytere@gmail.com>
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Khaidi Chu <i@2333.moe>