Implement F1AP RRC Version encoding/decoding in CU&DU

RRC Version is a required IE. Hence, implement the encoder and decoder
for this message. At the DU and CU, read the RRC Version we use and fill
the corresponding field.

Co-authored-by: Robert Schmidt <robert.schmidt@openairinterface.org>

openair2/COMMON/f1ap_messages_types.h

@@ -152,7 +152,10 @@ typedef struct f1ap_setup_req_s {
   // F1_Setup_Req payload
   uint64_t gNB_DU_id;
   char *gNB_DU_name;
-  
+
+  /// rrc version
+  uint8_t rrc_ver[3];
+
   /// number of DU cells available
   uint16_t num_cells_available; //0< num_cells_available <= 512;
   struct {
@@ -188,6 +191,10 @@ typedef struct f1ap_setup_resp_s {
   /// number of DU cells to activate
   uint16_t num_cells_to_activate; //0< num_cells_to_activate <= 512;
   served_cells_to_activate_t cells_to_activate[F1AP_MAX_NB_CELLS];
+
+  /// rrc version
+  uint8_t rrc_ver[3];
+
 } f1ap_setup_resp_t;
 
 typedef struct f1ap_gnb_cu_configuration_update_s {