This is part of #395.
This is ability needs to work on any machine, not just the cookcountyjail.recoveredfactory.net server, and the retrieved data must be delivered in a parsiimonious manner.
Also need to be able to know what dates are available.
Acceptance criteria:
- Get list of available dates
- Ability to arbitrarily fetch any of the available snapshots in a way that does not require that all of the data exist in the caller's space.
- Has a documented behavior if given a data that does not exist and the implementation matches the documented behavior