Case C-397/21: Judgment of the Court (Seventh Chamber) of 13 October 2022 (request for a preliminary ruling from the Fővárosi Törvényszék — Hungary) — HUMDA Magyar Autó-Motorsport Fejlesztési Ügynökség Zrt. v Nemzeti Adó- és Vámhivatal Fellebbviteli Igazgatósága (Request for a preliminary ruling — Harmonisation of fiscal legislation — Common system of value added tax (VAT) — Directive 2006/112/EC — Sales which are not subject to VAT — VAT unduly invoiced and paid — Liquidation of the provider — Refusal by the tax authority to refund to the customer VAT improperly paid — Principles of effectiveness, tax neutrality and non-discrimination)