Clarify that a cluster has not been created due to an error

Description

When adding a new GKE cluster in CI/CD > Kubernetes, if you specify a non-existing GCP project you receive an error, but the cluster entry on GitLab is already created (I suppose due to the async nature of the process).

In the list of clusters, you now have the entry with a switch that is not on or off, but "disabled on". This may be not clear to users, since no information is available unless they enter into the details view. Also, the same flag is working in the details view.

Proposal

We could add some note in the list view saying the cluster has not been created because of an error. Also, we can make the behavior of the two switches consistent, whichever is the choice.