By SARA VANDEN BERGE   Foster’s Home for Children is gearing up for its largest fundraiser of the year.   The 23 rd  annual auction will take place on Saturday, March 7, on the foster home campus in Stephenville.     The live and silent auctions take place from 9 a.m. – 2 p.m.   Doug Young, president of Foster’s Home for Children, told Beneath the Surface News that the annual auction is the organization’s biggest fundraiser of the year.   “We will have used vehicles, fiberg