v3 refactor (#1868)

* Move to v3

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

server/mucp/mucp.go

@@ -2,10 +2,14 @@
 package mucp
 
 import (
-	"github.com/micro/go-micro/v2/server"
+	"github.com/micro/go-micro/v3/server"
+)
+
+var (
+	DefaultRouter = newRpcRouter()
 )
 
 // NewServer returns a micro server interface
 func NewServer(opts ...server.Option) server.Server {
-	return server.NewServer(opts...)
+	return newServer(opts...)
 }