Merge Feature/repl-to-node

This merge request contains updates to support choosing which nodes we replicate data to in Chronopolis.

Before we merge we want to check that:

• We send the correct replicating nodes when adding collections
  • ingest-rest/BagController
  • intake-shell/IntakeProducer
  • others
• We have test coverage for the changes
  • Creating replication objects (ingest-rest/ReplicationTask)
  • Creating bag objects (ingest-rest/StagingController)