Update redux namespace(s) state to clusters state.

[absoludity]

The main change here is just:

export interface IClusterState {
  currentNamespace: string;
  namespaces: string[];
  error?: { action: string; error: Error };
}

interface IClustersMap {
  [cluster: string]: IClusterState;
}

export interface IClustersState {
  currentCluster: string;
  clusters: IClustersMap; 
}

Note that IClusterState (singular) is almost identical to what INamespaceState was (just s/current/currentNamespace). This change allows us to store the state of each cluster separately (including the current namespace which the user was using). The rest of the changes are just refactoring to the new format.

Ref: #1762

[andresmgot]

LGTM

[andresmgot]

isn't this a lint issue? I would say that it forces this to be cluster,

[absoludity]

Strangely not, it seems. Updated.

[andresmgot]

clusterReducer

[andresmgot]

Let me know if I have to re-review something

[absoludity]

Let me know if I have to re-review something

Nope, there's only two commits since your review:

• 1ab6f1a - from your feedback
• 1ab6f1a - adding a similar wait (with a TODO comment) for the CI test based on your debugging last Friday.