Review endpoints describe their response fields, and four responses are corrected

Retrieve widget site reviews, Retrieve reviews for a user, the site bottom line, the synchronous Create review and the other review endpoints now describe their response fields. Four responses now match what the API returns:

• Top mentioned topics returns {"top_topics": {...}} with no status or response wrapper.
• Retrieve product data returns storeId and productId (camelCase), not store_id and product_id.
• Retrieve product data and Search reviews return 404 with the plain-text body Account not found for an unknown store ID.