Custom resource to delete Personalize resources

[james-jory]

Since the Personalize resources (schemas, datasets, solutions, campaigns, event tracker) are all created outside of CloudFormation by a notebook or Lambda function, they are not cleaned up automatically when the Retail Demo Store stack is deleted. Although there is a Personalize Cleanup Notebook that can be used to delete these resources, it would be easy to miss or forget to run through this notebook before deleting the stack. Once the stack is deleted, the notebooks are deleted too. In addition, if the user initially deploying the stack chooses to have the Personalize campaigns auto-created post-deployment, it's not apparent that the cleanup notebook should be run. This could leave behind resources that will continue to incur unexpected charges.

To ensure that Personalize resources created as part of the Retail Demo Store deployment are cleaned up when the stack is deleted, a custom resource should be created that deletes these resources.