add tag support

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

api/annotations.proto

@@ -17,6 +17,7 @@ syntax = "proto3";
 package micro.api;
 
 import "api/http.proto";
+import "api/micro.proto";
 import "google/protobuf/descriptor.proto";
 
 option go_package = "github.com/unistack-org/micro-proto/api;api";
@@ -29,3 +30,13 @@ extend google.protobuf.MethodOptions {
   // See `HttpRule`.
   HttpRule http = 72295728;
 }
+
+extend google.protobuf.MethodOptions {
+  // See `MicroMethod`.
+  MicroMethod micro_method = 65535655;
+}
+
+extend google.protobuf.ServiceOptions {
+  // See `MicroService`
+  MicroService micro_service = 65535655;
+}