SAN FRANCISCO — Just about nothing is going right for the Giants’ offense, but Casey Schmitt has been the lone exception. On Monday, he hammered his fifth home run of the season and is responsible for their past three trips around the bases dating back to last Saturday. Giants utility player Casey Schmitt has been the breakout star for the team despite a very underwhelming performance from the Giants as a whole. AP Consider the versatile 27-year-old’s breakout a rare bright spot in an otherwise dreadful start. Schmitt has been so good, in fact, and the Giants so bad, that he may need to acquire some new equipment. An outfielder’s mitt. Manager Tony Vitello wasn’t just kidding around when he said Schmitt, who plays all four infield positions, could add corner outfield to his portfolio — just to keep his bat in the lineup. “It’s a definite possibility,” Vitello said before Schmitt homered again in Monday’s 3-2 win over the Padres .…