Fix best-seller ORDER BY handling to prevent SQL syntax errors

[CySSoO]

Motivation

• Prevent malformed or ambiguous ORDER BY clauses in best-seller queries that could produce SQL syntax errors (observed error near LIMIT).
• Ensure cache keys reflect the normalized ordering parameters so cached results match the actual SQL ordering.

Description

• Normalize and validate orderBy and orderWay inputs inside getBestSellingProductIds, getBestSellingProductIdsByBrand, getBestSellingProductIdsByFeature and getBestSellingProductIdsByFeatureValue by mapping allowed names to explicit SQL columns via an $allowedOrderBy map and deriving $orderColumn.
• Force orderWay to an uppercase ASC/DESC fallback and use pSQL($orderColumn) and pSQL($orderWay) in the generated SQL ORDER BY to avoid injection/invalid identifiers.
• Update cache keys to include the normalized $orderColumn instead of the raw orderBy string so cached entries correspond to the actual SQL ordering.

Testing

• No automated tests were executed for this change.

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Codex Task