Revert CRA kick if a liquidation awaits settlement

[EdNoepel]

Description

Prevent kicking a Claimable Reserve Auction (CRA) if a liquidation auction is pending settlement.

Purpose

• Several pool actions require actors to settle unsettled liquidations. CRA auctions should not be kicked if a liquidation is pending settlement, because reserves may be needed to clear bad debt.
• Resolves Kirill audit issue M-07 (https://github.com/k1rill-fedoseev/audits/blob/master/solo/Ajna.md)

Impact

Expect small gas cost in kickReserveAuction and increase in contract size. Specifically, ERC721Pool size increased from 98.97% to 99.02%. ERC721 unit tests were unchanged, and median gas for the call increased from 64977 to 67372.

Tasks

• [x] Changes to protocol contracts are covered by unit tests executed by CI.
• [x] Protocol contract size limits have not been exceeded.
• [x] Gas consumption for impacted transactions have been compared with the target branch, and nontrivial changes cited in the Impact section above.
• [x] Scope labels have been assigned as appropriate.
• [x] Invariant tests have been manually executed as appropriate for the nature of the change.

[EdNoepel]

Investigating regression test breakage. The affected test does not involve a reserve auction.

[EdNoepel]

I had been investigating a baffling regression test failure. After doing a foundryup I was unable to reproduce the behavior. Reran CI job a second time and the problem went away.

[MikeHathaway]

Is this attack still feasible with the removal of reserves covering bad debt?