Changes to GET /private/get_positions

the error response's property type changed from integer to object for status 400

removed the required property message from the response with the 400 status

added the optional property error/data to the response with the 400 status

added the required property error/code to the response with the 400 status

added the required property error/message to the response with the 400 status

the result/items/allOf[#/components/schemas/position]/leverage response's property type changed from integer to number for status 200

added the required property result/items/allOf[#/components/schemas/position]/user_id to the response with the 200 status

the response property result/items/allOf[subschema #2]/estimated_liquidation_price became optional for the status 200

the response property result/items/allOf[subschema #2]/open_orders_margin became optional for the status 200

the response property result/items/allOf[subschema #2]/estimated_liquidation_price became nullable for the status 200