Also push the onconnect event for the initial connection.
This still doesn't properly handle sending an onconnect event to a
pre-existing SharedWorkerGlobalScope with the same name for the same
origin, but it does give us a lot of WPT passes in the SharedWorker
category.
Instead of wrapping all non-movable members of TransportSocket in OwnPtr
to keep it movable, make TransportSocket itself non-movable and wrap it
in OwnPtr.
