Add support for MessageChannel and MessagePort

[gerdstolpmann]

These two classes are actually part of the web worker story, and you quickly need them when two workers want to communicate autonomously (w/o parent). They also exist in node, but a again in a little bit different way.

[Pyrolistical]

web api: https://developer.mozilla.org/en-US/docs/Web/API/Channel_Messaging_API
node api: https://nodejs.org/docs/latest-v16.x/api/worker_threads.html#class-messagechannel