(pipelines): (Add feature to display all changesets for stage before manual approval step)

### Describe the feature

I would like to "run" all changesets of a stage at first, then have a manual approval step and then perform the execute change set in the original run-order.

### Use Case

The use case is, that we would like to check the changesets for all stacks of an environment, to be able to perform a qualified manual approval.

### Proposed Solution

_No response_

### Other Information

_No response_

### Acknowledgements

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

### CDK version used

2.63.2

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

Linux a-3pq6x6lu5kukl 5.15.86-53.137.amzn2.x86_64 #1

No files, tests, or entry points are named. Start by locating the CDK Pipelines stage, manual-approval, and change-set execution flows, then determine how the requested pre-approval display and original run order should interact; done means the workflow is implemented and covered by tests.

Written by the indexing model from the issue text.