[feature] stream CloseSend (#2323)

* support stream CloseSend

* move CloseSend into Closer

examples/stream/rpc/server/main.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"log"
+
+	proto "github.com/asim/go-micro/examples/v4/stream/rpc/server/proto"
+	"go-micro.dev/v4"
+)
+
+type Streamer struct{}
+
+// Server side stream
+func (e *Streamer) ServerStream(ctx context.Context, req *proto.Request, stream proto.Streamer_ServerStreamStream) error {
+	fmt.Printf("ServerStream Got msg %v\n", req.Count)
+	for i := 0; i < int(req.Count); i++ {
+		fmt.Println("sent", i)
+		if err := stream.Send(&proto.Response{Count: int64(i)}); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Bidirectional stream
+func (e *Streamer) Stream(ctx context.Context, stream proto.Streamer_StreamStream) error {
+	fmt.Println("Stream")
+	for {
+		req, err := stream.Recv()
+		if err == io.EOF {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+		fmt.Printf("Got msg %v\n", req.Count)
+		if err := stream.Send(&proto.Response{Count: req.Count}); err != nil {
+			return err
+		}
+	}
+}
+
+func main() {
+	// new service
+	service := micro.NewService(
+		micro.Name("go.micro.srv.stream"),
+	)
+
+	// Init command line
+	service.Init()
+
+	// Register Handler
+	proto.RegisterStreamerHandler(service.Server(), new(Streamer))
+
+	// Run service
+	if err := service.Run(); err != nil {
+		log.Fatal(err)
+	}
+}