Handle fetching and storing metric data in data store instead of Metric content model class

[terryttsai]

Is your feature request related to a problem? Please describe.
Right now in our content models we have a bunch of metric classes that handle fetching and storing its own data. The issue with these classes is that we now have to connect them to our userStore so that they can get the auth token from the userStore. So right now we have to pass in a reference to that userStore to each generated metric content model.

Describe the solution you'd like
One idea is that we should match the pattern in case-triage and justice-counts where we have a separate API datastore that handles fetching and storing data. We might want to use our content model classes to generate the type of data we want to fetch, then use our API store to handle fetching and storing data?