By Andrew Mills and Maya Gebeily AL KHOR, Qatar (Reuters) -The World Cup kicked off in Qatar on Sunday with the Muslim nation, which faced a barrage of criticism over its treatment of foreign workers, LGBT rights and social restrictions, staking its reputation on delivering a smooth tournament. Qatar’s Emir Sheikh Tamim bin Hamad al-Thani arrived at the stadium flanked by FIFA president Gianni Infantino, to a roaring crowd, and took their seats alongside other Arab leaders. A show then unfolded on the pitch, featuring three camels, American actor Morgan Freeman and a performance of a new tourn…