Add CI test to force RRC IDLE and new connection setup with 5G-S-TMSI
This MR is a follow up to !2725 (merged)..
The primary goal is to introduce a CI test that enforces the following behavior:
- Forces the UE to enter RRC_IDLE state.
- Validates the UE's re-connection procedure using the 5G-S-TMSI as the UE identity.