✨ feat(PricesContainer): implement usePrices hook and replace reducer if needed

[acasazza]

🎯 Overview

PricesContainer currently uses the old reducer-based pattern for fetching and managing prices. The usePrices hook (from @commercelayer/hooks) already exists and provides a cleaner, SWR-based approach — consistent with how SkusContainer, SkuListsContainer, and AvailabilityContainer were migrated in #750.

🚀 Goals

• Replace the reducer-based price fetching in PricesContainer with the usePrices hook
• Remove or simplify PriceReducer if it becomes redundant after the migration
• Pass interceptors from CommerceLayerContext to usePrices (consistent with feat(#748): add interceptors prop to SDK hooks and CommerceLayer component #750)
• Maintain full backward compatibility for existing props and children

✅ Acceptance Criteria

• PricesContainer uses usePrices hook internally
• PriceReducer removed or simplified if no longer needed
• interceptors forwarded from context to the hook
• Existing tests pass; new tests added if needed
• 100% coverage maintained for affected files