Add F1 handover CI test

This MR introduces a CI test for F1 handover by reusing the existing F1 RFSIM CI test. The objective is to integrate a handover (HO) test into the current pipeline, where the UE operates as an rfsim server.

The test involves triggering the handover process three times: an iperf test is conducted after the first handover, followed by ping tests after the second and third handovers.

A few minor fixes have been added in the process.