Implement active period feature for JDBC mode with a HAPI source server

[rayyang29]

trafficstars

In PR #277, the JDBC based search mode of the batch pipeline is implemented. We should also implement the active period feature for this mode.

The active period feature, specified by the flag --activePeriod, allows users to get all the historical resources (encounters and observations) associated with patients who are active within a specified time-frame.

[bashir2]

Marking this as P3 until we make a decision on whether we want to continue maintaining activePeriod as a feature. If we do, there are also other improvements we need to do; so better to look at this feature holistically when it becomes a priority again.