CODE128: reduce extended latch cut-off from 5 to 4 for better

encodation in certain cases (and no pessimizations found so far),
  props lyngklip (BWIPP);
  fix extended char latching when exactly 3 extended chars at end;
  count code set C (not digits) in loop deciding when to
  shift/latch to extended for better estimate
AZTEC: return warning if ECC < 5% (due to bit-stuffing when version
  given); return error if > 22 layers (Zint 26) for Reader
  Initialisation symbol requested for better error message
AZTEC/HANXIN/QRCODE: consolidate different ECC data size tables
  into one indexed by ECC
DBAR_EXP: check for reduced length <= 77 up front for better error
  message
HANXIN: use `malloc()` rather than `z_alloca()` for large binary
  array
QRCODE: `ecc_level` now 0-based (not 1-based)
MICROQR: consolidate different version end routines into one
  `microqr_end()` and use new `microqr_data` table to simplify code
MICROPDF417: use table for max codewords per column
library: centralize all error messages using new `errtxt()`,
  `errtxtf()`, `errtxt_adj()` funcs that protect `symbol->errtxt`
  from overflow, & try to make error messages more consistent
  thru-out, adding more feedback info to many, & use positional
  args "%n$" in prep for l10n (maybe);
  `is_sane/is_sane_lookup()` -> `not_sane/not_sane_lookup()`,
  returning 1-based position (zero on failure) instead of bool;
  `long` ints -> plain `int` (except those dealing with `ftell()`,
  `fread()` etc) as depend on int being 32-bits already
GUI: in "grpDATF.ui" use "PlainText" rather than "RichText" for
  tracker ratio examples as height of text messing up sometimes
manual: clarify Codablock-F length maximum & add examples
docs: README: pandoc 3.5, Ubuntu 24.04
CMake: use "-Wpedantic" for Clang only as GNU complains about
  `errtxtf()` positional args "%n$"

backend/code128.h

@@ -38,6 +38,7 @@ extern "C" {
 
 /* Allow for a reasonable number of special Code Set escapes and for GS1 AI delimiters */
 #define C128_MAX    256
+#define C128_MAX_S  "256" /* String version of above */
 
 INTERNAL int code128(struct zint_symbol *symbol, unsigned char source[], int length);