AbortSignal support for the subscriber client

[danmichaelo]

A screenshot that you have tested with "Try this API".

This problem applies specifically to the Node.js client. It's not an issue with the API itself.

What would you like to see in the library?

A way to abort cleanly when the service needs to exit (without setting a very low timeout). It would be nice if the pull method supported AbortSignal like so since AbortSignal is becoming the standard way to abort promises:

const abortController = new AbortController();
const client = new v1.SubscriberClient({ projectId });

const [response] = await client.pull({
  subscription: subscriptionId,
  maxMessages: 100,
}, {
  signal: abortController.signal   <-- This
});

Describe alternatives you've considered

No response

Additional context/notes

No response

[feywind]

@danmichaelo This is a timely issue because I've been thinking about how/if we could use AbortController in the library. There's an effort to add more graceful shutdown processes, and this might be part of that, too.