Goal
As a user, I need the ability to connect my existing clusters (in OCM) to the new kcp backend to make them available as compute targets for app deployment 

Background
Users need to take some action in the CLI in order to make existing ocm clusters kcp-aware. The OCM cluster list and kcp connected clusters are two separate lists so we need to teach ocm users about this new transparent multi-cluster service and help users seamlessly connect clusters and understand the value of doing so. 

Requirements

• Introduce the kcp service 
• provide an action to connect individual clusters to kcp
• Consider primary and secondary actions after user runs sync agent to connect cluster
• determine what to do for cases where a cluster has already been connected. Can we tell? If so, should the action change to send users to compute area to continue building compute workspaces/creating locations in order to further teach users? 
• stretch goal: add column in cluster list to indicate connection status (if technically feasible) 
• Work with content team on UI copy and align with CCS (fyi wolfeallison adonahue@redhat.com)