Although it has been recognized that the existence of property interests are often determined by reference to sources such as state law, see Georgia v. Randolph, 547 U.S. __, 126 S.Ct. 1515, 1540 (2006) (Scalia, J., dissenting), South Carolina courts have embraced federal takings jurisprudence as providing the rubric under which we analyze whether an interference with someone???s property interest