datapath-windows: Add port friendly name to OVS_VPORT_ENTRY

datapath-windows: Add port friendly name to OVS_VPORT_ENTRY

The port friendly name will be set by WMI / powershell script.
It will be used from within the netlink command vport new to
identify the hyper-v switch port it represents.

This patch also adds a function to lookup a vport by the
port friendly name.

Signed-off-by: Samuel Ghinet <sghinet@cloudbasesolutions.com>
Co-authored-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Acked-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Eitan Eliahu <eliahue@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Tested-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>