Case C-546/19: Judgment of the Court (Fourth Chamber) of 3 June 2021 (request for a preliminary ruling from the Bundesverwaltungsgericht — Germany) — BZ v Westerwaldkreis (Reference for a preliminary ruling — Area of freedom, security and justice — Immigration policy — Return of illegally staying third-country nationals — Directive 2008/115/EC — Article 2(1) — Scope — Third-country national — Criminal conviction in the Member State — Article 3(6) — Entry ban — Grounds of public policy and public security — Withdrawal of the return decision — Lawfulness of the entry ban)