Migrate socket tests to new test server

This includes at least
  * socket/qhttpsocketengine/tst_qhttpsocketengine.cpp

• socket/qsocks5socketengine/tst_qsocks5socketengine.cpp
• socket/qtcpserver/tst_qtcpserver.cpp
• socket/qtcpsocket/tst_qtcpsocket.cpp
• socket/qudpsocket/tst_qudpsocket.cpp

 
Additional tests might need changes.