bring identity interface inline with discovery interface

[richardcase]

What this PR does / why we need it: This makes the identity provider interface consistent with the discovery provider interface. Validation/Resolve has been implemented for both types of providers in the app

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged): Fixes #320