Protected containers: Protection rules in project settings ui

What does this MR do and why?

• Adds frontend ui for the container protection rule in project settings
• Hide project setting for container protection rules when relevant feature flag is disabled
• This frontend -related MR uses the GraphQL API to interact with the backend
• This MR is part of the epic "protected containers", see Container Registry: Granular protection for rep... (&9825)
• This MR just focusses on listing the existing container protection rules for this project
• Form for creating, updating and deleting protection rules will be part of follow-up MRs, see #441345 (closed)

🛠 with ❤ at Siemens

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

MR Checklist (@gerardo-navarro)

• Changelog entry added, if necessary
• Documentation created/updated via this MR
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the javascript style guides
• Conforms to the database guides

Screenshots or screen recordings

Screenshot of the list container container protection rules.

When there is an error while fetching the container protection rules, we get the following alert message.

How to set up and validate locally

1. In rails console enable the experiment fully

Feature.enable(:container_registry_protected_containers)

2. Create some container protection rules to show in the table

15.times { |i| ContainerRegistry::Protection::Rule.create(project: Project.find(7), repository_path_pattern: "flightjs/flight#{i}", push_protected_up_to_access_level: :maintainer, delete_protected_up_to_access_level: :developer) }

3. Go to http://gdk.test:3000/flightjs/Flight/-/settings/packages_and_registries and scroll down a bit
4. See the list of protection rules

Related to #441345 (closed)