ST. LOUIS — Like many young baseball players, Aaron Senne dreamed of fame and fortune when he signed his first contract as a Miami Marlins’ draft choice after a record-breaking college career at Missouri. Reality as a low-level minor leaguer was far different: vending machine dinners, bug-infested apartments and a paltry salary with an equivalent hourly wage less than what fast-food workers make. Senne and former minor-league players in each of the 30 big-league organizations are suing Major League …