Paging (F1AP): refactor CU_send_Paging() to use PAGING message

- Add F1AP_PAGING message type and macro; F1AP defines Paging, not
  Paging Indication. CU task now handles F1AP_PAGING instead of
  F1AP_PAGING_IND.
- In CU_send_Paging(): take const f1ap_paging_t *; replace inline
  ASN.1 encoding with encode_f1ap_paging(); refine memory management;
  clean up in the process

Note: F1AP_PAGING_IND definitions left in place and still used in the
RRC callback - to be removed in a follow-up commit.

openair2/COMMON/f1ap_messages_def.h

@@ -64,4 +64,5 @@ MESSAGE_DEF(F1AP_UE_CONTEXT_MODIFICATION_CONFIRM, MESSAGE_PRIORITY_MED, f1ap_ue_
 MESSAGE_DEF(F1AP_UE_CONTEXT_MODIFICATION_REFUSE, MESSAGE_PRIORITY_MED, f1ap_ue_context_modif_refuse_t, f1ap_ue_context_modification_refuse)
 
 /* CU -> DU*/
+MESSAGE_DEF(F1AP_PAGING, MESSAGE_PRIORITY_MED, f1ap_paging_t, f1ap_paging)
 MESSAGE_DEF(F1AP_PAGING_IND, MESSAGE_PRIORITY_MED, f1ap_paging_ind_t, f1ap_paging_ind)

openair2/COMMON/f1ap_messages_types.h

@@ -69,6 +69,7 @@
 #define F1AP_UE_CONTEXT_RELEASE_COMPLETE(mSGpTR)   (mSGpTR)->ittiMsg.f1ap_ue_context_release_complete
 
 #define F1AP_PAGING_IND(mSGpTR)                    (mSGpTR)->ittiMsg.f1ap_paging_ind
+#define F1AP_PAGING(mSGpTR)                        (mSGpTR)->ittiMsg.f1ap_paging
 
 /* Length of the transport layer address string
  * 160 bits / 8 bits by char.