Add Jsonl formatter, add ability to optionally use raw stream name

[alexmaras]

I wanted to be able to have the key be identical to the stream name without any suffixing in order to be able to control my files a little more easily, as the filename changes were interrupting my use-case - syncing an azure storage location to S3.

I've added a jsonl format option too, as that's what I'm syncing across.