NetworkPkg: Use the New Functions from HttpLib

After submitting changes for HttpLib, other modules should be able to use
those functions
1 remove the private function and their calls
2 update it with the functions from httpLib

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ghazi Belaam <Ghazi.belaam@hpe.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Samer EL-Haj-Mahmoud <elhaj@hpe.com>
Reviewed-by: Jiaxin Wu <jiaxin.wu@intel.com>

NetworkPkg/HttpUtilitiesDxe/HttpUtilitiesDxe.inf

@@ -2,6 +2,7 @@
 #  Implementation of EFI Http Utilities Protocol interfaces.
 #
 #  Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
+#  (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
 #
 #  This program and the accompanying materials
 #  are licensed and made available under the terms and conditions of the BSD License
@@ -30,7 +31,6 @@
 [Sources]
   HttpUtilitiesDxe.h
   HttpUtilitiesDxe.c
-  HttpUtilitiesImpl.c
   HttpUtilitiesProtocol.c
 
 [LibraryClasses]
@@ -41,6 +41,7 @@
   BaseLib
   UefiLib
   DebugLib
+  HttpLib
 
 [Protocols]
   gEfiHttpUtilitiesProtocolGuid               ## PRODUCES