Support complex-path for wsteth

[talbaneth]

This is using the new callee for wsteth.

[godsflaw]

I ran and simulated an WSTETH-A and WSTETH-B liquidation. One problem did arise, after the first run, I received this error for WSTETH-A, but it was resoled on restart:

Checking auction opportunities for WSTETH-A
(node:38433) UnhandledPromiseRejectionWarning: Error: value out-of-bounds (argument=null, value=-5, code=INVALID_ARGUMENT, version=abi/5.3.0)
    at Logger.makeError (/home/satoshi/src/makerdao/auction-demo-keeper/node_modules/@ethersproject/logger/lib/index.js:187:21)
    at Logger.throwError (/home/satoshi/src/makerdao/auction-demo-keeper/node_modules/@ethersproject/logger/lib/index.js:196:20)
    at Logger.throwArgumentError (/home/satoshi/src/makerdao/auction-demo-keeper/node_modules/@ethersproject/logger/lib/index.js:199:21)
    at NumberCoder.Coder._throwError (/home/satoshi/src/makerdao/auction-demo-keeper/node_modules/@ethersproject/abi/lib/coders/abstract-coder.js:41:16)
    at NumberCoder.encode (/home/satoshi/src/makerdao/auction-demo-keeper/node_modules/@ethersproject/abi/lib/coders/number.js:46:18)
    at /home/satoshi/src/makerdao/auction-demo-keeper/node_modules/@ethersproject/abi/lib/coders/array.js:74:19
    at Array.forEach (<anonymous>)
    at Object.pack (/home/satoshi/src/makerdao/auction-demo-keeper/node_modules/@ethersproject/abi/lib/coders/array.js:60:12)
    at TupleCoder.encode (/home/satoshi/src/makerdao/auction-demo-keeper/node_modules/@ethersproject/abi/lib/coders/tuple.js:71:24)
    at AbiCoder.encode (/home/satoshi/src/makerdao/auction-demo-keeper/node_modules/@ethersproject/abi/lib/abi-coder.js:93:15)
(node:38433) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)
Already processing opportunities for WSTETH-B

I was able to kick off a WSTETH-B auction right restart and the same error also occurred, also resolved by a keeper restart. I'm able to reproduce it sometimes by resetting the entire simulation, going to try and track this down.

[godsflaw]

I cannot reproduce now, and the error trace would indicate we have a problem with the route coming back here as that gets thrown into the abi encoder, and is the only thing that changed. That being said, if we have some problem here, we have it in the other codepaths too. I'm inclined to say, there is something here, but not related to this PR.

[godsflaw]

simulations look good, approved!