Add grpc_validator

grpc/scripts/gen.bat

@@ -13,10 +13,12 @@ for %%A in (%*) do (
   if "%%A"=="go" (
     set plugin=protoc-gen-go
     where /q !plugin! || echo Missing !plugin! && exit /b
+    set vplugin=protoc-gen-govalidators
+    where /q !vplugin! || echo Missing !vplugin! && exit /b
     set out=%gen%\go
     if not exist !out! mkdir !out!
     echo Generating Go code
-    !exec! --go_out=plugins=grpc:!out! %pbs%
+    !exec! --go_out=plugins=grpc:!out! --govalidators_out=!out! %pbs%
   )
   if "%%A"=="gohttp" (
     set plugin=protoc-gen-grpc-gateway