Case C-333/18: Judgment of the Court (Tenth Chamber) of 5 September 2019 (request for a preliminary ruling from the Consiglio di Stato — Italy) — Lombardi Srl v Comune di Auletta, Delta Lavori SpA, Msm Ingegneria Srl (Reference for a preliminary ruling – Review procedures on the award of public supply and public works contracts – Directive 89/665/EEC – Action for annulment of the decision awarding a public contract by a tenderer whose bid was unsuccessful – Counterclaim brought by the successful tenderer – Admissibility of the main action in the event that the counterclaim is well founded)