RICHARD COWAN and DOINA CHIACU  A bipartisan group of U.S. lawmakers have unveiled a $908 billion COVID-19 relief bill aimed at breaking a monthslong deadlock between Democrats and Republicans over new emergency assistance for small businesses, unemployed people, airlines and other industries during the pandemic. The measure has not yet been written into legislation. Nor has it been embraced yet by the Republican Trump administration, Democratic President-elect Joe Biden or leaders in the Senate or House of Representatives, all of whom would be needed for passage. But it comes with the backing of a group of conservatives and moderates who…