Streams should be transferable

[ilogico]

What is the problem this feature would solve?

Web Streams should be transferable to other Workers.
This is implemented in Firefox and Chromium.
This allows sending messages between threads without wrapping them in MessageEvents.

What is the feature you are proposing to solve the problem?

Allow Streams to be transfered.

What alternatives have you considered?

This is not implemented in Webkit, Node, or Deno.