Instead of passing the payload for Workers directly to `.onmessage`,
perform something more similar to what the browser API provides,
namely create an event object with a `.data` property.
This does not make `MessagePort` implement the `EventTarget` API, nor
does it implement the full `MessageEvent` API, but it would make
such extensions non-breaking changes if we desire them at
some point in the future.
(This would be a breaking change if Workers were not experimental.
Currently, this method is also undocumented and only exists with
the idea of enabling some degree of Web compatibility.)
PR-URL: https://github.com/nodejs/node/pull/26082
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>