Adds empty state component for GAR integration settings

What does this MR do and why?

Adds empty state component for GAR integration settings

If google_cloud_platform_workload_identity_federation_integration does not exist on project, integrations_helper is updated to return:

• path to Google Cloud Identity and Access Management settings page.
• editable as false.

Renders empty_state component when above path exists.

MR acceptance checklist

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Screenshots or screen recordings

Proposal	After

How to set up and validate locally

1. Enable container registry in the gdk https://gitlab.com/gitlab-org/gitlab-development-kit/-/blob/main/doc/howto/registry.md#set-up-container-registry-to-display-in-ui-only

2. Simulate a SAAS instance in local GDK

3. In rails console enable the experiments

   Feature.enable(:gcp_artifact_registry)
   Feature.enable(:google_cloud_workload_identity_federation)

Flow 1

1. Visit Project > Settings > Integrations > Google Cloud Artifact registry
2. Empty state should be visible
3. Click on Set up Google Cloud IAM
4. Add settings.
5. Visit Project > Settings > Integrations > Google Cloud Artifact registry again
6. Empty state should be not be visible anymore.

Flow 2

1. Visit Project > Settings > Integrations > Google Cloud Artifact registry
2. Empty state should be visible
3. Visit Group > Settings > Integrations > Google Cloud IAM
4. Add settings.
5. Visit Project > Settings > Integrations > Google Cloud Artifact registry again
6. Empty state should be not be visible anymore.

Related to #439371 (closed)