[ndevenish]

So far overridable queue names have only existed on a subset of manually implemented dlstbx services e.g. dlstbx.services.per_image_analysis.

This centralises all of what was previously

workflows.recipe.wrap_subscribe(
            self._transport,
            "strategy",
            self.generate_strategy,
            acknowledgement=True,
            log_extender=self.extend_log,
        )

to

self.subscribe("strategy", self._generate_strategy)

with defaults set to match the common settings (Everything can still be overridden).

This also implements a universal mechanism for overriding the queue - ServiceStarter (used by zocalo.go and dlstbx.go) now adds it's own --queue argument (unless the caller already has their own). If this is set, or if the service "environment" dictionary has a queue/queues entry, or if the WORKFLOWS_QUEUE environment variable is set, then it will replace the defaults subscribed queue under the following rules:

• queuename=newname will replace the queue name if it matches exactly. Multiple entries can be space- or comma- separated.
• newname will replace the queue name only if the service subscribes to one (non-broadcast) queue - if a second queue is connected then an error will be raised.
• -q/--queue [NAME=]QUEUE can be passed multiple times to any frontend using ServiceStarter.