Initial implementation of OMEC/NGIC SPGW example

[nickolaev]

This includes a basic deplyment and a manual start of the DP. The NGIC image is compiled out of a separate repo to account for the new --no_veth which allows for using the AF_PACKET mode and vdev in the containerised/NSM version of the NGIC.

Signed-off-by: Nikolay Nikolaev [email protected]