Rename a workspace, or set its cost center label.

Organization admins only (403 organization_admin_required), on a browser session with a fresh proof in the x-50h-reauth header (401 reauth_required). It needs a person: API keys, connected apps and service accounts get 403 session_required. Every change is written to the organization's audit. costCenter null removes the label. The label is printed on the workspace's invoices from then on and carried on spend reports and exports. A closed workspace cannot change (409 workspace_closed).