(aws-codepipeline-actions): (CloudformationAction and its children do not expose variables)

### Describe the feature

The different CloudFormation actions in CodePipeline expose variables that are generated from the `Outputs:` section of the corresponding template.

Currently, https://github.com/aws/aws-cdk/pull/5604 is not implemented for `CloudformationAction` or any of its children.

Although https://github.com/aws/aws-cdk/pull/5604#issuecomment-1117652890 references that it is under consideration and an issue is open, I have not been able to find any issue (open or closed) tracking this, so I'm opening this one. If this is a duplicate please refer me to the original issue so I can follow its status

### Use Case

Referencing outputs from stacks without having to use string interpolation.

### Proposed Solution

_No response_

### Other Information

_No response_

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### CDK version used

2.100.0

### Environment details (OS name and version, etc.)

macOS 13.5.1

Start with the CloudformationAction and its child actions in the aws-codepipeline-actions module, then read pull request #5604 and its linked discussion for the existing variables approach. Trace how CloudFormation template Outputs should become CodePipeline variables and identify the relevant action variants. Done means all CloudFormation actions expose their generated Outputs consistently, with behavior covered by the project’s existing tests.

Written by the indexing model from the issue text.