Invariants improvements

[prateek105]

Description of change

High level

• Fix failing regression tests.
• Add invariant RE9.
• Remove repayDebtByThirdParty handler in SettleERC20PoolHandler, as repayment for borrower in auction is restricted.
• Add getBorrowerPenaltyAndKickerReward method to calculate borrowerPenalty and kickerReward from the event emitted.
• Move all calls to Pool and PoolInfo in single helper so to make code more easy to maintain (if pool/ utils interfaces are changed there should be only one place to update)
• Code cleanup

[ith-harvey]

Whats the status on this one @prateek105 ?

[prateek105]

Whats the status on this one @prateek105 ?

Invariants are working through 1000 runs and 20 depth fine. I was working on these before the audit tasks, I need to make one more improvement in the test suite which I am thinking of doing after we are done with audit tasks.

[EdNoepel]

Note that in testing on parvati, I have not encountered issues here which were not reproducable in develop branch.