COPENHAGEN/BERLIN (Reuters) -Seven people, including four suspected Hamas members, were arrested in Denmark, Germany and the Netherlands on suspicion of planning attacks on Jewish institutions in Europe, authorities in the three countries said on Thursday. The arrests were made as Israel pressed on with its operation to destroy Hamas in the Gaza Strip, a war that was touched off by a cross-border Oct. 7 assault on Israeli towns by militants of the Palestinian Islamist movement. Three of the suspects were detained in Berlin and another was detained in the Netherlands, all four longstanding memb…