Changes to Get list of items

for the query request parameter num_records, default value 25 was added

api operation id v2_get_item_list removed and replaced with get_item_list

added the new optional query request parameter sort_by

added the new optional query request parameter sort_order

for the query request parameter num_records, the type was generalized from integer to string

added the optional property data/items/items/developer_note to the response with the 200 status

the discount_percent response's property default value 0 was added for the status 200