FE: Use mapped/unmapped filters in Agent Authorization UI

MR: Pending

Description

In BE: Update query API to support listing of dire... (#455804 - closed), we merged two new filters for the remoteDevelopmentClusterAgents query: UNMAPPED/MAPPED . These are the filters that should be used instead of the AVAILABLE filter in the Agents Authorization UI.

Acceptance Criteria

• Replace the AVAILABLE filter with the MAPPED/UNMAPPED filters in the following GraphQL query: https://gitlab.com/gitlab-org/gitlab/-/blob/master/ee/app/assets/javascripts/workspaces/agent_mapping/graphql/queries/get_agents_with_mapping_status.query.graphql