Create database tables to support BBO framework

BBO (Batched background operations) is different from BBM framework in few major ways,

1. BBO tables can grow quickly than BBMs, as it can be triggered by user actions and cronjobs.
2. There can't be any manual intervention when things go wrong in BBOs, unlike BBMs.
3. There can be many operations targeting the same table.

Schema has to be designed keeping these in mind. Tables should be properly segregated and partitioned so that they can be deleted at the right time without eating up a lot of space.