…bscriber

this is safer approach since the original channel can be closed while configuring the queue due to application-level exceptions. So consumer channel shouldn't depend on configuration issues.

…ead of passing channel itself

(LT-5705): application-level exceptions can happen during channel configuration which leads to channel closure. In this case configurator might need to create another channel to proceed with configuration. Also this update separates subscription channel from configuration channel which is much safer.