Iran wants China to play a bigger role in brokering a nuclear deal to end the war with the United States and to potentially take custody of its highly enriched uranium, a philanthropist and businessman in close contact with Iranian negotiators told Newsweek.Despite a ceasefire in a war that has shaken the global economy because of its impact on Middle East oil exports, talks between the U.S. and Iran have stalled. Both sides have set out maximalist demands, with Iran refusing calls from President Donald Trump’s administration for a halt to all uranium enrichment, the curbing of missile forces and…