StackSet Details should show the list of target OU Names along side with their IDs

### Name of the resource

Other

### Resource name

CloudFormation StackSet

### Description

When we create a service managed StackSet, we need to mention the target "Organizational IDs" or we can deploy to whole Organization. However, after creating the StackSet with "Deploy to organizational units (OUs)" option, in the "StackSet info" section it shows the list of target Organizational unit IDs. However, It would be more feasible if we have "OU Names" or OU tree structure with it's child OUs along, which shows all the path where this StackSet's instances are deployed upon. This will enhance the readability when there are many accounts where the StackSet's instances are deployed on.

### Other Details

_No response_

The issue names no repository files, tests, or entry points; first determine where StackSet details are rendered and how target OU IDs are obtained. Done means the details view shows target OU names or a readable OU hierarchy alongside their IDs for deployments to selected OUs.

Written by the indexing model from the issue text.