a top-level or static function,
which asynchronously creates a ferry client, given a some params.
the messageMainPort can be used to send arbitrary messages from the isolate to main
from example for token refresh. You can also create a ReceivePort here and send
its sendPort to the messageHandler for establishing a two-way communication.
if you don't pass a messageHandler, the sendMessageToMessageHandler SendPort will be null.
