By Rajesh Kumar Singh CHICAGO (Reuters) – U.S. carriers including Delta Air Lines and United Airlines are betting big on American consumers’ unquenched thirst for travel across the Atlantic by adding more flights to Europe. U.S. airlines are responding to consumers emboldened by a more powerful U.S. dollar and more flexible work arrangements that allow them to work from wherever they want, extending the travel season into the fall, industry officials said. “For Americans going to Europe, it’s getting a bargain with currencies,” Delta’s Chief Executive Ed Bastian told Reuters. “Europe is probab…