Added the Health Check List component

What does this MR do and why?

In order to support customers in diagnosing problems with Duo AI features, which are powered by Cloud Connector, we are introducing a "health check component" that runs several tests and flashes green or red depending on the outcome.

This is just a first iteration and we will evolve this more later on.

This change is behind the cloud_connector_status feature flag. It should not be user-facing currently.

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.

Screenshots or screen recordings

Error	Success	Mix

How to set up and validate locally

To check the UI of the component:

1. Run yarn storybook:install && yarn storybook:build && storybook:start in your Terminal
2. The storybook will be opened automatically. In the left-hand navigation panel go to EE -> usage_quotas -> code_suggestions -> health_check_list to see the different component states as presented in the screenshots above

To test functionality:

1. In your rails console run: Feature.enable(:cloud_connector_status)
2. Make sure you have Duo Pro setup
3. Go to a group, which has Duo Pro enabled (gitlab-org in my case)
4. Go to Settings -> GitLab Duo
5. You should see the Run health check button on the top right. Click it
6. You should get the list of the Health checks

Related to #474860 (closed)