By Elizabeth Piper and William Schomberg LONDON (Reuters) – Elected for the first time to parliament in 2015, Rishi Sunak became Britain’s youngest prime minister in more than 200 years on Monday, tasked with steering the country through an economic crisis and mounting anger among some voters. It is a remarkable return for Sunak who lost a leadership bid to Liz Truss less than two months ago when he was accused by some in the Conservative Party of bringing down their hero, Boris Johnson. One of the wealthiest politicians in Westminster, he enters Downing Street facing a need to make deep publi…