Sovereign immunity — Foreign States and State-owned corporations — Expropriation of assets by foreign State — Action for restitution against Algerian company holding expropriated assets — Whether company entitled to jurisdictional immunity or immunity from execution — Whether foreign State expropriation without adequate compensation can be recognised in municipal courts — Whether Algerian company an entity independent from Algerian State — Acts iure gestionis and iure imperii — Whether assets of company distinct from those of Algerian State — The law of France