[Kubernetes Dashboard] K8s Tree needs to key off of cluster.id

[qcorporation]

Description and Rationale

Based upon the changes being made within the K8sMD ticket: https://github.com/elastic/k8smd/issues/60
There is a gap within K8sMD retrieval of the Cluster Name within EKS. There is no standard/generalized way of capturing the Cluster Name reliably. As such, we need to consider that the Cluster Name might not exist. Within the UI, the tree view keys off of this identifier to create the top level root for visualizing the tree,
[
[cluster name, namespace, pods, container],
[cluster name, nodes, pods, containers]
]
The K8s Dashboard needs to key off of the cluster.id as defined within Ticket 60
If the cluster name is present, display the cluster name within the UI.
If the cluster name is not present, display the cluster.id for now (Suggestions are welcome here @nick-alayil )

Acceptance Criteria:

• Running Endpoint+K8sMD within EKS will properly group cluster resources if the cluster name is empty within the UI
• Unit test MUST be created to test Cluster Name is empty

[qcorporation]

@m-sample had a suggestion of separating some attributes into different fields.
Then, if Endpoint+K8sMD did not populate the cluster name field, we can display it within the UI (root node) based upon a combination of other fields.