Agent status page: add integration status area - iteration 1

As a part of the work related to adding the integration status to the agent list page we should add an integration UI moment to the agent details page.

Proposal

• Add a page header as per the design.
• Show the integration status of the agent.
• Show the Premium features.
• Show a "Valid access token" message when the agent is connected.
• Show "No access token" if the token is absent.

Connected	Not connected	Never connected