gs1/gs1_lint: update to latest gs1-syntax-dictionary, removing

`iso3166list` linter and adjusting all others to allow for
  multiple optional linters (by checking `data_len` vs `offset`)
library: change invalid `input_mode` reset to return warning;
  split func table into 2 - func declarations without prototype
  will be error in C23;
  make invalid symbology check a separate function using a table
  and call near beginning of `ZBarcode_Encode_Segs()`;
  in `ZBarcode_BarcodeName()` save some bytes by simplifying
  name table and removing "BARCODE_" prefix from entries
output: fix pack logic to use pragma by default (actually more
  portable than `__attribute__`)
common.h: remove C99 detection which was artifice of specifying
  "-std=", and rejig layout to be more logical
BWIPP: update to latest version
general: change `ZINT_VERSION_BUILD` tests to `#if`s
general: further fiddling with some tables to save a few bytes
CLI: change function arg `optarg` -> `arg` so doesn't shadow
  global
general: library now compilable with Comp Cert C (though as it
  doesn't support `alloca()` will have multiple memory leaks)

backend/pcx.h

@@ -1,7 +1,7 @@
 /*  pcx.h - header structure for ZSoft PCX files */
 /*
     libzint - the open source barcode library
-    Copyright (C) 2016-2022 Robin Stuart <rstuart114@gmail.com>
+    Copyright (C) 2016-2024 Robin Stuart <rstuart114@gmail.com>
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -37,7 +37,7 @@
 extern "C" {
 #endif
 
-#ifdef _MSC_VER
+#ifdef OUT_USE_PRAGMA_PACK
 #pragma pack(1)
 #endif
 
@@ -62,7 +62,7 @@ extern "C" {
         uint8_t filler[54];
     } OUT_PACK pcx_header_t;
 
-#ifdef _MSC_VER
+#ifdef OUT_USE_PRAGMA_PACK
 #pragma pack()
 #endif