Show how to use Temporal as a queue

[Ozoniuss]

This example shows how you can use Temporal's event history and workflow input as a queue. It implements a batching mechanism where a workflow continuously listens for incoming signals, as well as a timer, and processes the batch when the timer fires, followed by restarting the timer. The workflow keeps track of the number of incoming events and decides to continue-as-new when there are too many events recorded in the event history, passing the accumulated events in the next workflow's input.

What was changed

Added a new example.

Depending on how complicated the change is, I think it may be worth it to add a Ticker to the workflow API (e.g. workflow.NewTicker) since we already also have Timer. I think it would at least be a nice addition to the Go SDK (implemented with Timers), if not worthy as a Temporal feature.

Why?

This seemed to be a nice pattern in situations where you need some sort of queue to batch operations, but you only have a Temporal cluster available and no event streaming platform. It likely doesn't reach the same performance as say Kafka for extremely high throughput, but it should be good enough for a large amount of use-cases.

I needed to write a similar PoC, so I thought I'd share it here as well.

Checklist

1. How was this tested:
   Local Temporal cluster, also explained in readme.