XNAP: add logging support and update ASN.1 runtime sources

- Add XNAP component to the logging framework in log.h
  - Introduce LEGACY_XNAP log message definitions (INFO, ERROR, WARNING, DEBUG, TRACE)
    in T_messages.txt for tracing and debugging XNAP procedures
  - Update xnap_R16.2.0.cmake formatting for consistency
  - Add missing ASN.1 runtime sources required by XNAP (e.g. asn_codecs_prim_xer.c,
    BIT_STRING_print.c, BIT_STRING_rfill.c, etc.)

common/utils/LOG/log.h

@@ -162,6 +162,7 @@ static const char *const flag_name[] = {FOREACH_FLAG(FLAG_TEXT) ""};
   COMP_DEF(USIM, log)           \
   COMP_DEF(F1U, )               \
   COMP_DEF(X2AP, )              \
+  COMP_DEF(XNAP, )              \
   COMP_DEF(M2AP, )              \
   COMP_DEF(M3AP, )              \
   COMP_DEF(NGAP, )              \