Incorrect pnl calculation when closing a force closed position

[holzeis]

🤔 I don't think this is how we calculate PNL.

The payout is already collateral_reserve + trader_margin +/- pnl. So to get the PNL you would have to subtract collateral_reserve and trader_margin.

Originally posted by @luckysori in https://github.com/get10101/10101/pull/2513#discussion_r1594880159