Change NATS retention policy to Workqueue #13
Description
Currently we are using the limits policy in NATS to enable the queues to retain data for the purpose of "handling failure" on the processing/emitting side.
In practical terms, we only need to use the message once, and so the workqueue model is more applicable here.
The docs cover this in more detail here: https://docs.nats.io/nats-concepts/jetstream/streams#retentionpolicy
This has been tested in Proton succesfully, and we will bring the changes here in a new PR