mod needs to evolve to handle multiple, concurrent user identities #85
Description
A user-mod / end-mod can evenually have multiple user identities from different identity providers. So we'll need to redesign for that. A RawDataService will need to figure out, which one of those user identities the one it should use.
Knowing about a RawDataService's organization behind it should help match it to one of the existing identities's provider / organization, if it's the same, but some API can accept identities from multiple providers, so we need to add to RawDataService the knowledge of what kind of identities it can accept / work with.
A criteria or a list of criteria to evaluate on identities, such that if the evaluation returns true the identity can be used by the raw data service should do the trick.