By Parisa Hafezi and Angus McDowall DUBAI, July 6 (Reuters) - Iran's theocratic rulers are mobilising mass crowds of the revolutionary faithful on the streets of Tehran, but behind the display of unity it is far from clear they have resolved gaping internal fractures over the economy and state repression. Vast numbers are attending a week of funeral events for Supreme Leader Ayatollah Ali Khamenei, killed in U.S.-Israeli strikes at the start of the war, in mourning ceremonies, marches and demons