Case C-421/18: Judgment of the Court (First Chamber) of 5 December 2019 (request for a preliminary ruling from the Tribunal de première instance de Namur — Belgium) — Ordre des avocats du barreau de Dinant v JN (Reference for a preliminary ruling — Judicial cooperation in civil matters — Regulation (EU) No 1215/2012 — Jurisdiction and the recognition and enforcement of judgments in civil and commercial matters — Article 7(1)(a) — Special jurisdiction in matters relating to a contract — Concept of ‘matters relating to a contract’ — Claim for payment of annual fees payable by a lawyer to a bar association)