Support for DL pdr in session establishment

Signed-off-by: kharade rohan.kharade@openairinterface.org
@tien-thinh.nguyen @phine_stefan

This PR is to support changes required for SD-Fabric UPF integration. sd-fabric-sess-est-mod-ok-test.pcapng

Following things are not yet addressed, and I propose to handle it in another PR -

• Add URR, currently sd-fabric upf does not supports session reporting (usage report supported in data plane)
• Add NWI, URR can be verified with these changes using VPP-UPF, provided we need to fix adding NWI IE too.
• Validation of UL CL using SD-Fabric UPF
  • We might need to configure multiple SD-Fabric hardaware switches or BESS UPF is possible,
  • Moreover we need more changes on SMF side as well