Hive Engine - Improved robustness and logging

This minor release includes the following:

• new config setting defaultLogLevel , to control amount / noisiness of logging. Set to warn by default.
• enhanced logging for debugging purposes
• logging now done using the loglevel library
• default sort by _id index for database queries, to prevent dependency on MongoDB "natural" order (fixes a cause of forking in some rare circumstances when smart contracts don't explicitly specify an index to sort by)

PRs included: #123 #133

Note that loglevel was added to the packages in this release, so when upgrading you must also do npm ci --only=prod

Also, the format of package-lock.json was changed to version 2, but this remains backward compatible with npm version 6 for those of you who are not running the latest npm.