Create new directed graph (DG) for 5G PNF pre-check, upgrade and post-check. 

If the payload contains pnf-flag and it is set to true then that indicates request for PNF. 

If it is set to false, then the request is for VNF, and we will use vnf-id in input and nf-naming-code in payload.

nf-naming-code = vgw for example.

SDNC will look up nf-naming-code in AAI if not passed in payload.

For PNF, we will use the following in payload:

1) pnf-name

2) ipaddress-v4-oam