Fix dateTime filtering operators producing incorrect results

[kac-axelor]

• DateTime comparison operators were not working correctly when filtering by DateTime fields
• Root cause: cleanResult used JSON.parse(JSON.stringify(...)) which serialized Date objects to ISO strings, causing TypeORM to receive strings instead of Date instances as query parameters
• Fix: replaced the JSON round-trip with a manual recursive clean function that correctly handles all supported field types — preserving Date and Buffer instances for the pg driver, and calling toJSON() on custom types like BigDecimal to avoid double-serialization