[feature] stream CloseSend (#2323)

* support stream CloseSend

* move CloseSend into Closer

client/client.go

@@ -64,6 +64,7 @@ type Response interface {
 
 // Stream is the inteface for a bidirectional synchronous stream
 type Stream interface {
+	Closer
 	// Context for the stream
 	Context() context.Context
 	// The request made
@@ -80,6 +81,12 @@ type Stream interface {
 	Close() error
 }
 
+// Closer handle client close
+type Closer interface {
+	// CloseSend closes the send direction of the stream.
+	CloseSend() error
+}
+
 // Option used by the Client
 type Option func(*Options)