move common code file in common directory

remove several unused files
remove mem_block_t that is never used in a different way than a simple heap buffer
move up IP address type and remove duplications of the same struct declaration

openair2/SDAP/nr_sdap/nr_sdap.h

@@ -22,7 +22,7 @@
 #ifndef _NR_SDAP_GNB_H_
 #define _NR_SDAP_GNB_H_
 
-#include "openair2/COMMON/platform_types.h"
+#include "common/platform_types.h"
 #include "common/utils/LOG/log.h"
 #include "nr_sdap_entity.h"
 

openair2/SDAP/nr_sdap/nr_sdap_entity.h

@@ -24,7 +24,7 @@
 
 #include <stdint.h>
 #include <stdbool.h>
-#include "openair2/COMMON/platform_types.h"
+#include "common/platform_types.h"
 #include "openair2/LAYER2/nr_pdcp/nr_pdcp_entity.h"
 #include "NR_RadioBearerConfig.h"