Add support for additional ECR resource types via Cloud Control API

[sstoops]

This PR registers the following additional resource types via the Cloud Control API:

• AWS::ECR::PublicRepository
• AWS::ECR::PullThroughCacheRule
• AWS::ECR::RegistryPolicy
• AWS::ECR::ReplicationConfiguration

It also registers AWS::ECR::Repository as a duplication of the existing ECRRepository module.

Testing

Using an internal AWS Account, I've created one of each type of resource and checked there they are all removed by these changes.

I would note that AWS::ECR::PublicRepository appears to only be available in the us-east-1 region, so if you have other regions configured (I only tested us-west-2), you will receive an error message like this for those regions:

ERRO[0005] Listing AWS::ECR::PublicRepository failed:
    TypeNotFoundException: The type 'AWS::ECR::PublicRepository' cannot be found.

This error is only for those regions that do not support this resource type and that resource type is successfully cleaned up from the us-east-1 region.

Discussion

I've seen the discussion elsewhere that registering each Cloud Formation namespace using registerCloudControl() is a temporary solution to resolve some potential conflict with existing modules. As I foresee needing to add support for many more resource types via the Cloud Control API, should I count on continuing the workflow outlines in this PR until further notice?