[rbc] DataInputChannel, DataOutputChannel

[JooHyung Kim]

Subject
@AgwaB

Detail
For send input to BBA from ACS, ACS need to check whether matching RBC instance done its task. Instead of polling result from RBC, whenever RBC done its task send its result to ACS. So suggest DataInputChannel, DataOutputChannel

// whenever RBC done its broadcasting send its result to DataInputChannel
type DataInputChannel interface {
	Send(data Data)
}
// ACS receive broadcast result from RBC
type DataOutputChannel interface {
	Receiver() <-chan Data
}