Swift C++ std::list wrapper test

stdListTest.swift

  let list = SwiftListWrapper(dataSize: 1)
  list.push_back(value: "1".data(using: .utf8)!)
  list.push_back(value: "2".data(using: .utf8)!)
  list.push_back(value: "3".data(using: .utf8)!)
  list.push_front(value: "0".data(using: .utf8)!)

  XCTAssertEqual(list.size(), 4)

  XCTAssertEqual(String.init(data: list.front()!, encoding: .utf8), "0")

  let it = list.begin()

  let _ = it.increment()
  let _ = it.increment()

  XCTAssertEqual(String.init(data: it.value()!, encoding: .utf8), "2")