Merge remote-tracking branch 'origin/n2-handover-minor-fixes' into integration_2025_w40 (!3655)

The goal of this MR is to resolve memory leaks, prevent crashes, and improve code quality.

Bug Fixes:
- Fix crash in get_du_for_ue when F1 UE data doesn't exist during N2 handover
- Fix memory leaks in handover preparation and UE context cleanup
- Fix duplicate handover request handling with proper UE context validation

Code Quality Improvements:
- Prevent ASN.1 double-free bug in NGAP memory management (caller ownership
  principle)
- Fix hardcoded instance 0 bug in UE context release command
- Refactor e1_send_bearer_updates into three specialized functions with
  extracted common code
- Replace impossible ID mismatch checks with DevAssert statements
- Fix inconsistent equality checking patterns in E1AP bearer context management
- Improve error message consistency across NGAP handover functions
- Optimize PLMN identity assignment using struct copies

Documentation Enhancements:
- Improve RRC neighbor configuration documentation with actual parameter names
- Add same-machine setup guidance for N2 handover with network configuration
  notes
- Fix grammar errors and standardize naming conventions

Follow up to !3334 (merged)

ci-scripts/xml_files/container_5g_rfsim_n2_ho.xml

@@ -31,9 +31,6 @@
  000002
  000003
  020001
- 020002
- 030001
- 030002
  000004
  040001
  050001
@@ -110,7 +107,7 @@
                 <nodes>acamas</nodes>
                 <svr_id>rfsim5g_ue</svr_id>
                 <svr_node>acamas</svr_node>
-                <ping_args>-c 100 -i 0.25</ping_args>
+                <ping_args>-c 50 -i 0.25</ping_args>
                 <ping_packetloss_threshold>5</ping_packetloss_threshold>
         </testCase>
 
@@ -121,7 +118,7 @@
                 <nodes>acamas</nodes>
                 <svr_id>rfsim5g_ext_dn</svr_id>
                 <svr_node>acamas</svr_node>
-                <ping_args>-c 100 -i 0.25</ping_args>
+                <ping_args>-c 50 -i 0.25</ping_args>
                 <ping_packetloss_threshold>10</ping_packetloss_threshold>
         </testCase>