ncpcalls: use descriptive names for NCP wrapper functions

Rename the low-level NCP wrapper functions in ncpcall.c and net.h to include
both the NCP function/subfunction number and the operation they perform.

This keeps the numeric protocol reference visible for comparison with SDK
documentation and MARS-NWE logs, while making call sites easier to understand.
Update all callers to use the new names.

No behavior change.

nwdebug.c

@@ -47,7 +47,7 @@ int func_debug(int argc, char *argv[], int mode)
   else return(usage());
   level = atoi(argv[2]);
   if (level < 0 || level > 99) return(usage());
-  result = ncp_17_02(module, level);
+  result = ncp17_02_set_debug_level(module, level);
   if (result < 0) {
     fprintf(stderr, "set debug failed\n");
     fprintf(stderr, "perhaps you did not enable FUNC_17_02_IS_DEBUG\n");