Harden range filter labels against malformed values

[Betafer]

What

This PR makes range filter label generation resilient to malformed range values coming from the faceted search URL.

SearchProvider::labelRangeFilters() currently passes active range values directly to formatNumber() / formatPrice(). If a crafted URL provides a non-numeric range boundary, for example an HTML-like string, PrestaShop can throw a localization/decimal parsing exception while rendering category facets.

The change adds a small numeric boundary guard: valid numeric scalar values are preserved, invalid values fall back to the facet min/max, and a final 0 fallback is used only if both values are invalid.

Why

This prevents category/listing pages from failing when bots or malicious requests submit malformed price/weight range boundaries.

Tests

• php -l src/Product/SearchProvider.php
• php -l tests/php/FacetedSearch/Product/SearchProviderTest.php
• PHP_CS_FIXER_IGNORE_ENV=1 vendor/bin/php-cs-fixer fix --no-interaction --dry-run --diff --config=.php_cs.dist src/Product/SearchProvider.php tests/php/FacetedSearch/Product/SearchProviderTest.php
• Live validation on a PrestaShop 8 production/stage install: malformed q=Prezzo-<a><a><a><a><a>-100 AJAX category requests now return HTTP 200 and valid rendered products/facets instead of throwing cannot be interpreted as a number.

Note: the full legacy PHPUnit 5 suite could not run in my local environment because it is incompatible with PHP 8.1 (Cannot acquire reference to $GLOBALS).

[ps-jarvis]

Hello @Betafer!

This is your first pull request on ps_facetedsearch repository of the PrestaShop project.

Thank you, and welcome to this Open Source community!