Review and add more ACs for liquidation strategy

[gordsport]

With the introuction of the [Liquidation improvements] Completely decouple MTM, margin checks and closeout trades spec changes and core implementation/fixes there is a need to review and add ACs as the testing of this feature commences.

There have been a number of issues found in Market Sim that maybe should be covered in tests.

We should also be adding an AC for a happy path whereby we verify all balances are correct via the APIs.