Implement rollback during create handlers with typescript plugin

Hello,

I'd like to write a custom type using the typescript plugin. The docs talk about [progress chaining](https://docs.aws.amazon.com/cloudformation-cli/latest/userguide/resource-type-develop-stabilize.html) but it's not clear to me exactly how to write a simple plugin that:

1. First calls one AWS service
2. Then calls another AWS service, and if this step fails, retry it, or rollback the first step so that we don't accumulate dangling resources.