GANDHINAGAR, India, July 16 (Reuters) – U.S. Treasury Secretary Janet Yellen said on Sunday she was "eager" to work with China on areas of mutual interest, including debt restructurings for poorer countries, and that multilateral development banks needed reforms before capital increases could be considered. In remarks prepared for a press conference before a meeting of Group of 20 finance ministers and central bankers in India, Yellen said her visit to Beijing last week helped put the U.S.-China relationship on "surer footing" and that the world's two biggest economies had an obligation to the world "to cooperate on areas of…