client: improve option naming, add BatchPublish to noop client

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

client/client.go

@@ -40,6 +40,7 @@ type Client interface {
 	Call(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
 	Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
 	Publish(ctx context.Context, msg Message, opts ...PublishOption) error
+	BatchPublish(ctx context.Context, msg []Message, opts ...PublishOption) error
 	String() string
 }