Intent to ship: Transferable streams

[Kagami Rosylight]

As of Firefox 103 I intend to turn dom.streams.transferable.enabled on by default on all platforms. It has been supported by Blink since 2020 while not by WebKit yet.

Bug to turn on by default: https://bugzilla.mozilla.org/show_bug.cgi?id=1770627

Standard: link to the standard: https://streams.spec.whatwg.org/#rs-transfer, https://streams.spec.whatwg.org/#ws-transfer, https://streams.spec.whatwg.org/#ts-transfer

This feature was previously announced in this "Intent to prototype" thread: https://groups.google.com/a/mozilla.org/g/dev-platform/c/ACDDMOE-PPM.