ShellPkg: Update 'ifconfig -r' implementation

ShellPkg: Update 'ifconfig -r' implementation

This patch is used to update ifconfig -r implementation
to sync with UEFI Shell 2.2.

option -r means to reconfigure all or specified interface,
and set DHCP policy. If specified interface is already set
to DHCP, then refresh the IPv4 configuration.

If the interface name is specified
with '-r', DHCP DORA process will be triggered by the policy
transition (static -> dhcp).

Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Cc: Carsey Jaben <jaben.carsey@intel.com>
Cc: El-Haj-Mahmoud Samer <samer.el-haj-mahmoud@hpe.com>
Cc: Subramanian Sriram <sriram-s@hpe.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Sriram Subramanian <sriram-s@hpe.com>
Reviewed-by: Jaben Carsey <Jaben.carsey@intel.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>