MANILA — Allegations that the front-runner in the Philippine presidential election had a large sum of money in an undeclared bank account were not resolved Monday, allowing the issue to hang over the final week of the closely fought race. Trillanes, who is running for vice president and is backing a rival candidate of Duterte in the May 9 race, went to the Bank of the Philippine Islands and met with the mayor’s lawyer but said the questioned account was not opened for scrutiny. Riot police stood by to maintain order in the business district where Trillanes’ supporters also came, carrying posters that read: “We don’t want corrupt candidates.”