Jahangir Hajiyev was running out of money. That was the urgent subject before the board of a company based in the tax haven of Guernsey in September 2015. For years, Hajiyev, then chairman of the International Bank of Azerbaijan, had used a chain of trusts and shell companies stretching from Cyprus to the Channel Islands to move tens of millions of dollars out of the state-owned lender, according to allegations in U.K. court filings.