In case SWAP is not going to be added next version: Please allow "trading cost" snippets

In case of SWAP is not going to be added next version: Please allow a "trading cost" snippet to modify the orders list (P/L, swap/commission etc) at some point BEFORE the orders are accessed by any of the statistics functions. In this way, we could program SWAP in any way we want and could have it included in all the stats in every task without the need for whatif as well as all MC tests and all optimizations.