[UBI] Refactor and improve SD-Fabric tests

Proposers

• Georgios P. Katsikas

Description

All P4 SD-Fabric tests are restructured as follows:

• src/tests/p4-sd-fabric-sbi-connectivity/ contain L2, L3, and INT tests via the TFS SBI
• src/tests/p4-sd-fabric-svc-connectivity/ contain L2, L3, and INT tests via the TFS Service API
• src/tests/p4-sd-fabric-svc-upf/ contain UPF tests via the TFS Service API

Acknowledgements

This work is funded by the European Commission through the HORIZON-JU-SNS-2023 PROTEUS-6G project with Grant Agreement number 101139134.