Container registry cleanup preview shows the To be kept tab (MVC followup)

Context

This issue is part of an epic for the MVC solution for Container Registry cleanup policies. The epic has more details about the customer problem and scope of this MVC.

Problem to solve

When setting cleanup policies for the container registry, it's not possible preview how the policies you have set will be executed. The user should be able to test and verify the expiration policy settings without waiting for another tag expiration loop.

Designs

• Figma file for epic, including responsive designs

Scope of this issue

Container Registry cleanup preview MVC: show li... (#370329) adds a list of tags that will be deleted by the cleanup policy, per image repository. This issue adds a list of items that are not removed by the cleanup policy. That list is in a separate tab.

• The list of items to be kept is capped at 100 for now
• The list may not have pagination - pagination is handled in a separate issue (#370331)
• This issue may happen before or after the issue adding sort/filter functionality. It's possible that there is not yet a search bar in the UI
• tags the explicitly protected by cleanup rules have a natural language sentence under the reason for protection column on the preview table (e.g. name contains release)
• tags that are not explicitly protected by rules have nothing written in the reason for protection column
• empty state is no tags will be kept
• follows the same rate limiting as showing the list of items to be deleted (issue)