WIP-Security audit fixes

[gregscullard]

Detailed description: Fixes a number of issues identified through 3rd party security audit, see list of issues below.

• Add integration tests to Getters for input validation testing
• Remove hardcoded user/password/schema for the database
• Checks that an auction is PENDING before setting to ACTIVE
• Manage validators as a single message/call, and add transaction support so that all succeed or fail as one
• Adds transaction support to database updates involving one or more bids and an auction
• Removes first image from FileCoin if the second fails to be stored
• Fix potential NPE in PostAuctionHandler
• Removes emptyTestClient() constructor
• Removes setTesting methods
• Ensures all mirror queries have sorting order specified
• Auction readiness watcher thread checks auction is indeed pending when started
• Additional test coverage

Which issue(s) this PR fixes: Fixes #138 Fixes #137 Fixes #143 Fixed #144 Fixed #145 Fixes #146 Fixes #147 Fixes #148 Fixes #149 Fixes #150 Fixes #151

Special notes for your reviewer:

• Note changes to .env file with respect to the database properties

Checklist

• [X] Documentation added
• [X] Tests updated