Add ability to Write to GCP PubSub with an orderingKey
There was a prior email dev thread about PubSub ordering key[1] but that was in reference to reads. It should be possible to support pubsub Write with ordering key. We might be able to have users supply a serializable function to extra the ordering key from each message, for example?
Imported from Jira BEAM-13148. Original Jira may contain additional context.
Reported by: egalpin.