MedmodulePkg: Refine codes related to Dhcpv4 and Dhcpv6 configuration.

MedmodulePkg: Refine codes related to Dhcpv4 and Dhcpv6 configuration.

Add a new head file Dhcp.h in Mde/Include/IndustryStandard, normalize the
universal option numbers and other network number tags.

Cc: Sriram Subramanian <sriram-s@hpe.com>
Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Cc: Wu Jiaxin <jiaxin.wu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Zhang Lubo <lubo.zhang@intel.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>