Currently, the CursorResponseBuilder, operates on BSONObj to create the output for find, agg and getmore commands. However, once we complete SERVER-119296, SERVER-119294 and SERVER-119262, we should be able to modify CursorResponseBuilder to be more strongly typed and thus, allow find, agg and getmore to implement typedRun() and build a typed Reply object.

The main challenge here is that we currently have 2 types of Cursor replies:
1. CursorInitialReply which is used by find and agg to return the initial batch
2. CursorGetMoreReply which is used by getmore for all subsequent batches.

We should be able to use templating to allow us to have strongly typed versions of CursorResponseBuilder for both.