Plenty of SF Giants prospects have thrived this spring against big-league competition, but five stood above the rest. Spring training is the best time every year to get an early look at which prospects are trending toward a breakout season. As the SF Giants continue cutting down their big-league roster in preparation for Opening Day, it’s worth taking a look at some prospects who have excelled against top-flight competition. Here are five SF Giants prospects who stood out for their play and where they are development-wise in this year’s spring training: Be sure to check out Giants Baseball Insider’s top…