User story:

As the number of regions expands, querying all of them will become inefficient. The cluster list should only query regions known to have clusters visible to the current user.

Acceptance criteria:

• The application will make requests to get clusters only from regions that are known to have clusters. 
  • An example regional request to get clusters: 

    https://api.aws.ap-southeast-1.stage.openshift.com/api/clusters_mgmt/v1/clusters 

• The application will not make requests to regions that are known to not have clusters.

NOTE: The application will know what regions are known to have clusters by first calling the new API endpoint constructed in OCM-6091