Use Redis instead of Etcd to keep track of proxy worker routes

Let’s use Redis instead of Etcd to store the app proxy worker’s route configurations (for both Traefik and aiohttp), to prevent write burdens to the etcd cluster.

With a high write volume, etcd requires explicit compaction (and auto-compaction configuration) to keep the API latency consistently low.

- TODO: Check if we could use the same Redis keys to sync routes to Traefik.

JIRA Issue: BA-2005