Batch liquidation txs for greater profits

[daniel-savu]

Problem

In case a borrower is very badly undercollateralized, several liquidations may be required to clear bad debt, because the close factor parameter restricts how big a single liquidation can be. This means that the bot may lose out on some of the liquidation premium if other liquidators get their tx included too.

Solution

Batch several as many liquidation extrinsics together as required to fully clear bad debt, possibly also including DEX transaction in the batch to ensure the conversion doesn't incur more slippage than expected.