Changes to GET /private/get_user_trades_by_instrument_and_time

the response property result/trades/items/mark_price became nullable for the status 200

the response property result/trades/items/matching_id became nullable for the status 200

the response property result/trades/items/order_id became nullable for the status 200

the result/trades/items/post_only response's property type changed from string to boolean for status 200

the result/trades/items/reduce_only response's property type changed from string to boolean for status 200

the query request parameter end_timestamp became optional

the query request parameter start_timestamp became optional

added the optional property result/trades/items/starbase_client_order_id to the response with the 200 status

added the optional property result/trades/items/block_trade_leg_count to the response with the 200 status

added the optional property result/trades/items/original_order_type to the response with the 200 status

added the optional property result/trades/items/starbase_order_id to the response with the 200 status