Investigate alternatives to file system cache

[jsaur]

We need a simple way to store key-value pairs to save state. Right now we're using an npm library (cache-manager) to get and set cache values. Initially this was an in-memory cache, but this caused issues during pod updates as memory was cleared. We then switched to a file-system cache, which solves that initial problem but makes deployments cumbersome, and doesn't scale well. Another solution supported by our cache-manager is redis, which would work well, it would just need to be deployed on our various environments as well as CNBS on-prem. Another option would be to create a simple table in postgres with two coluns, key + value, and use that. This would require either writing a plugin for cache-manager, or alternatively writing a class that mirrored cache-manager function signatures (there's only 3 or 4) and then swap it out everywhere.