ENG-4418: Add catalog tables and cartographer to the signature of
RejoinCoordinator.startJoin().
ENG-4418: Add a new type to RejoinMessage for table block data transfer.
ENG-4418: Extract snapshot restore and snapshot completion handling code from
RejoinProducer to JoinProducerBase so that JoinProducer can reuse it.
ENG-4418: Extract snapshot request related code from Iv2RejoinCoordinator to the
base class.
ENG-4418: Allow filtering tables for stream snapshot.

If the JSON data in the request specifies which tables the destination wants,
the source will only send data of those tables.
Remove unused import from RealVoltDB.
ENG-4418: Make the snapshot data queue unbounded in JoinProducer per Ariel's
comment.

The snapshot producing side already bounds the number of buffers that can be
generated at a time, so no need to bound them here.
Merge pull request #416 from VoltDB/ENG-4418

ENG-4418: Replicated table data transfer on join