Use Punycode filenames for non-ASCII TLD suffix data files

Some systems and tools (e.g., certain archive extractors, Windows
environments, or CI pipelines) do not properly handle non-ASCII
characters in file paths. The public suffix data files for
internationalized TLDs (such as ישראל, СРБ, 香港, and ไทย) were stored
using their native Unicode names, which caused installation failures
on those systems.

This commit converts those filenames to their Punycode equivalents
(e.g., XN--4DBRK0CE.php instead of ישראל.php) using `idn_to_ascii()`.
Both the data generation command (`UpdateDomainSuffixesCommand`) and the
runtime validator (`PublicDomainSuffix`) are updated to use the same
Punycode-based file lookup, ensuring consistency. A polyfill dependency
(`symfony/polyfill-intl-idn`) is added so that `idn_to_ascii()` is
available even when the `intl` PHP extension is not installed.

Assisted-by: Claude Code (Claude Opus 4.6)
Co-authored-by: Henrique Moody <henriquemoody@gmail.com>

Author: Copilot

composer.json

@@ -25,6 +25,7 @@
         "psr/container": "^2.0",
         "respect/string-formatter": "^1.6",
         "respect/stringifier": "^3.0",
+        "symfony/polyfill-intl-idn": "^1.33",
         "symfony/polyfill-mbstring": "^1.33"
     },
     "require-dev": {