Distributed zed lake service

[marktwallace]

This is the series of issues that we will use to track the implementation of an zqd service for internal use and demos. This will include parallel query execution using multiple zqd instances in a K8s cluster. It will not include a multi-tenant API. A caching layer will be a future epic following the patterns from the doc link below.

The high-level story of how this works is in a google doc: https://docs.google.com/presentation/d/1T4FTKvRrUwRGOq5lcQCgNoJERfUxtBSowP-e8UpQWYM/edit?usp=sharing