Case C-675/21, Strong Charon: Judgment of the Court (Seventh Chamber) of 16 February 2023 (request for a preliminary ruling from the Supremo Tribunal de Justiça — Portugal) — Strong Charon, Soluções de Segurança, S.A. v 2045-Empresa de de Segurança, S.A., FL (Reference for a preliminary ruling — Social policy — Transfers of undertakings — Safeguarding of employees’ rights — Directive 2001/23/EC — Scope — Refusal by the transferee to recognise the transfer of the employment contract — Definition of ‘transfer’ — Definition of ‘economic unit’ — Absence of a contractual link between the transferor and the transferee)