Perhaps too much fuss is being made over the defection of Celsion Corp. to New Jersey. Founded in Maryland in the 1980s, the Columbia-based biotech company has all of 18 employees. But Celsion is the kind of outfit that is supposed to represent Maryland’s economic future: a biomedical research boutique on the verge of launching a product, collecting revenue, booking profits and hiring dozens of workers. And it has decided it doesn’t want to do that here.