Join Cluster List and Cluster Request page using tabs.  Currently these are 2 separate pages, but we will join them using tabs.

Acceptance Criteria:

• New "Clusters" page will have tabs for Cluster Lists and Cluster Requests
• Update Navigation and routes so you can go to either tab: /clusters#list and /clusters#requests
• Fix Left nav to says Clusters (after we changed in to Cluster Lists not long along)
• Fix monitoring to look at Clusters/list or have /Cluster-list redirect to /Clusters#list