Enhance Order Retrieval with Updated Date Filtering

Currently, the Salla API provides order data, but it lacks an order updated date field and the ability to filter orders based on their last update. Adding these features will significantly improve efficiency for developers and merchants by allowing them to:

1. Retrieve orders based on the last update – Useful for syncing only modified orders instead of fetching all orders repeatedly.

2. Improve performance – Reduces unnecessary API calls and processing time by retrieving only relevant data.

3. Enable better order tracking – Helps merchants and third-party integrations track order progress based on changes like status updates, payment confirmations, or shipping modifications.

Proposed Enhancements:

Add an "updated_at" field in the order response to indicate the last modification date/time of an order.

Introduce a filter by "updated_at" in the "Get List of Orders" API, allowing users to fetch only orders updated within a specified date range.

This improvement will enhance data management and streamline workflows for merchants and developers integrating with the Salla platform.