Update econ.ComputeAgentData to handle liquidation value as a post-action stat

[Schwartz10]

https://github.com/glifio/go-pools/blob/281b47422f5d974879b33300b426ae06becba285/econ/econ.go#L52C25-L52C40 needs updating - liquidation value needs to handle the situation where a miner borrows, liquidation value goes up, then pledges it, discounting liquidation value