Use outstanding funding fees when considering liquidation

[luckysori]

A position can incur in a lot of unpaid funding fees, effectively reducing the margin and making liquidation more likely.

But the liquidation task doesn't know about this atm. We should probably update the Position every time we emit a new funding fee event.

Originally posted by @luckysori in https://github.com/get10101/10101/pull/2532#discussion_r1599407723