message: Add socketType to TestListenSocket
  Lost the merge race -- a new pure virtual method was added, which we
  needed to implement in the test class. This commit does so.
  Also changed up a few namespace scopes to be less verbose.
diff: @@ -128,20 +128,19 @@ TEST_P(ListenSocketImplTestTcp, BindSpecificPort) { testBindSpecificPort(); }
  */
  class TestListenSocket : public ListenSocketImpl {
  public:
  - TestListenSocket(Network::Address::InstanceConstSharedPtr address)
  - : ListenSocketImpl(-1, address) {}
  + TestListenSocket(Address::InstanceConstSharedPtr address) : ListenSocketImpl(-1, address) {}
  + Address::SocketType socketType() const override { return Address::SocketType::Stream; }
  };
  TEST_P(ListenSocketImplTestTcp, SetLocalAddress) {
  std::string address_str = "10.1.2.3";
  - if (version_ == Network::Address::IpVersion::v6) {
  + if (version_ == Address::IpVersion::v6) {
  address_str = "1::2";
  }
  - Network::Address::InstanceConstSharedPtr address =
  - Network::Utility::parseInternetAddress(address_str);
  + Address::InstanceConstSharedPtr address = Network::Utility::parseInternetAddress(address_str);
  - TestListenSocket socket(Network::Utility::getIpv4AnyAddress());
  + TestListenSocket socket(Utility::getIpv4AnyAddress());
  socket.setLocalAddress(address);
  