[FEATURE] Have some logic for dataset export/import

[aristizabal95]

Is your feature request related to a problem? Please describe.
We've noticed a common issue from real users related to moving from one machine to another. When this is done, users need to deal with our storage system, which can be cumbersome and error prone.

Describe the solution you'd like
Have something like medperf dataset export <ID> [-o path/to/output] and medperf dataset import <ID> to allow them to create a backup of the dataset and load it on another machine.