AWS::ECR::PublicRepository - (new GetAtt) Address/URI

### Name of the resource

AWS::ECR::PublicRepository

### Resource name

_No response_

### Description

VERY similar as this request for **Private** ECR's: https://github.com/aws-cloudformation/cloudformation-coverage-roadmap/issues/124

I'm trying to write a CloudFormation template around a public ECR, and codebuild that builds/pushes to it. I think I need:
- It's Arn (to add permissions for codebuild to push to it)
- It's RepositoryUri that I can pass into the codebuild as an environment variable, so it knows what to push to.

Unlike private ECR's, the Uri for public have an Account Alias tied to them. I can't find a way to grab that and craft what the Uri *should* be either. Is there any way to do this with Public ECR's?

(My use case needs to work on multiple accounts, so I can't hard-code the ecr alias. For now, I'll just pass it in as a parameter to not be blocked).

Thanks!

### Other Details

_No response_

Start by comparing this request with the linked private ECR issue #124 and reviewing the AWS::ECR::PublicRepository resource coverage. Confirm the required GetAtt values for the repository ARN and public repository URI, including the account alias, and verify that the resulting attributes support the described CodeBuild use case.

Written by the indexing model from the issue text.