By Angel Krasimirov SOFIA (Reuters) - Bulgaria's largest party GERB declined on Thursday to try to form a new government, opening the way for the rival Socialists to put together a technocrat administration and end a political impasse. Seeking to break a deadlock that could undermine the European Union's poorest economy, President Rosen Plevneliev immediately passed the baton to the Socialists, whose proposed government could be voted on next week. ...