v3 refactor (#1868)

* Move to v3

Co-authored-by: Ben Toogood <bentoogood@gmail.com>

client/mucp/mucp_response.go

@@ -0,0 +1,35 @@
+package mucp
+
+import (
+	"github.com/micro/go-micro/v3/codec"
+	"github.com/micro/go-micro/v3/transport"
+)
+
+type rpcResponse struct {
+	header map[string]string
+	body   []byte
+	socket transport.Socket
+	codec  codec.Codec
+}
+
+func (r *rpcResponse) Codec() codec.Reader {
+	return r.codec
+}
+
+func (r *rpcResponse) Header() map[string]string {
+	return r.header
+}
+
+func (r *rpcResponse) Read() ([]byte, error) {
+	var msg transport.Message
+
+	if err := r.socket.Recv(&msg); err != nil {
+		return nil, err
+	}
+
+	// set internals
+	r.header = msg.Header
+	r.body = msg.Body
+
+	return msg.Body, nil
+}