ROUEN, France — The best baseball in France was played on a recent Sunday afternoon in Rouen, on a spartan diamond beyond the soccer field at a municipal sports complex. Rouen’s team, the Huskies, swept a doubleheader against the Templiers of Sénart, outside Paris, on a cool, drizzly day when, at most, 35 spectators huddled under umbrellas on metal-and-plywood bleachers behind home plate.