Added multiline JSON outputter

[kszicsillag]

Added MultilineJsonOuputter, that

• exports one row -> one line in output file as standalone JSON document
• can process rows in parallel (AtomicFileProcessing=false)
• supports complex types (SQL.MAP, SQL.ARRAY)

Unit tests included

[msftclas]

All CLA requirements met.

[PeterAronZentai]

Any reason not pulling this? Test coverage seems proper.