Use Identity Server as authority and let it have support for multiple providers - augment tokens

[einari]

Maybe this belongs alongside User Management somehow and could be part of it??

Ability to augment tokens coming from multiple providers with additional claims that can be used during authorization.

A good example of this could be to have claims on every user saying which national society (Tenant) they have access to. This is not the Azure AD tenant ID - but something that enables us to check for authorisation if a particular user in a bounded context has access to the national society it claims to have.

Would it be an idea to have Identity Server infront of all this and augment the tokens with more information and let UserManagement interact with this and provide the mapping between users and what national societies they have access to.

See also #31, #327, #328, #510