MdeModulePkg: Define a general function to create DNS QName

MdeModulePkg: Define a general function to create DNS QName

This patch is used to define a general function to create
DNS QName.
QName is a domain name represented as a sequence
of labels, where each label consists of a length octet
followed by that number of octets. The domain name terminates
with the zero length octet for the null label of the root.

Cc: Hegde Nagaraj P <nagaraj-p.hegde@hpe.com>
Cc: El-Haj-Mahmoud Samer <samer.el-haj-mahmoud@hpe.com>
Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Hegde Nagaraj P <nagaraj-p.hegde@hpe.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Ye Ting <ting.ye@intel.com>