Extensible logstreams

[mattmoor]

/area API /area test-and-release /kind feature

I'd like to be able to extend the logstream (in Serving) to scrape things in the serving-tests namespace, e.g. to dump the queue-proxy logs for relevant resources.

cc @markusthoemmes @vagababov @coryrc

[github-actions[bot]]

This issue is stale because it has been open for 90 days with no activity. It will automatically close after 30 more days of inactivity. Reopen the issue with /reopen. Mark the issue as fresh by adding the comment /remove-lifecycle stale.

[vagababov]

/lifecycle frozen