Implement transfer logic for ArrayBuffer and ResizableArrayBuffer.
Change TransferDataHolder data type to Vector<u32> to reuse existing
serialization infrastructure.
Fix 5 WPT tests in `window-postmessage.window.html` that relates to
transport.
Fix `LibWeb/Text/input/Worker/Worker-postMessage-transfer.html`.
The latter is currently ignored due to flakiness, no rebaseline is
needed.
During serialization with transfer, initialize memory with known index
and initialize Serializer at position that dependent on the memory.
This is mandatory to make ArrayBuffer transport to work. It also happens
to fix 4 WPT tests, that are related to curcular references during
serialization.
The spec expects `postMessage()` to act as if it is invoked
immediately. Since `postMessage()` isn't actually invoked immediately,
keep tasks with source `PostedMessage` in the task queue, so that these
tasks are processed. Fixes a hang when `WorkerGlobalScope.close()` is
called immediately after `postMessage()`.
This aligns Workers and Window and MessagePorts to all use the same
mechanism for transferring serialized messages across realms.
It also allows transferring more message ports into a worker.
Re-enable the Worker-echo test, as none of the MessagePort tests have
themselves been flaky, and those are now using the same underlying
implementation.
