Draft: chore(ci): adding back LTE-UE Radio tests

• Found that libpython3.8 was not installed on the LTE-UE U20 image.
• Will use OAI-CN (w/ MAGMA-MME) to validate the LTE-UE
• Manually I was able to synchronize LTE-UE w/ gNB, do a full connection and ping the traffic-gen container
• New XML scenarios
• New pipeline: RAN-LTE-FDD-OAICN4G-Container trigger from RAN-Container-Parent