Agrega extension de search bar

ContactsApp/ContactsViewController.swift

@@ -144,3 +144,12 @@ extension ContactsViewController: UITableViewDelegate, UITableViewDataSource {
         
     }
 }
+
+extension ContactsViewController: UISearchBarDelegate, UISearchDisplayDelegate, UISearchResultsUpdating {
+    
+    func updateSearchResults(for searchController: UISearchController) {
+        <#code#>
+    }
+    
+
+}