Optimization: refactor how we parse actions/events for bid table

[kristiehuang]

Currently every time we auth user, or change chain, or submit a new Yobot tx, we fetch & reprocess ALL events across all users all projects? Hmm... how about just fetching events for just this user or for a particular project?

But currently the way it's done is that we parse ALL emitted events.......

Think about storing emitted events in some data struct so we can more efficiently query.
Related to issue #67 about off-chain data storage