Move retry logic to mongochangestream.

[dubiousdavid]

• Latest mongochangestream - Move retry logic to mongochangestream.
• Removed immutable option.

[daveyarwood]

I think this will accidentally result in there not being any retries in mongo2crate.

I was looking at this recently, and I noticed that there are a couple of try/catches in syncData.ts (example) around Crate operations, so if they fail, we're catching the error and emitting an "error" event instead. In that case, because no error is thrown, mongochangestream would not retry.

I think we need to remove the try/catches too, but it would also be good to ensure that only one "error" event is emitted at the end after the retries, which I think indicates that we need to emit the error event in mongochangestream. See my WIP PR: smartprocure/mongochangestream#30