By Emma FargeGENEVA, April 2 (Reuters) - Emergency medical needs in Iran are rising exponentially, and stocks of trauma kits and other gear could run low if the war persists, the head of the International Federation of Red Cross and ​Red Crescent ​Societies delegation there said on Thursday.More than 1,900 people have been killed since the U.S.-Israeli airstrikes on Iran began on February 28, and more than 21,000 injured, according to the agency - the only humanitarian group working across the c...