feat: apply change requests from PR review

* change `performAction.js` name to `submitBid.js`
* remove `Math.round` from `scale6`
* update indexing of bids and other constants in `config` object to improve readability (`auction.test.js`)
* move helper functions in `auction.test.js` to `test-lib/auction-lib.js`
* move `lib/vaults.mts` to `test-lib/vaults.mts`  and remove empty `lib` directory
* let it be known `sync-tools.js` is a stand-in code for Agoric#10171

Refs: Agoric/BytePitchPartnerEng#8

a3p-integration/proposals/n:upgrade-next/use.sh

@@ -5,4 +5,4 @@ set -e
 
 source /usr/src/upgrade-test-scripts/env_setup.sh
 
-./performAction.js
+./submitBid.js