Add ability to expose specific claims

[DerSimeon]

We use the OID to Identify the user. Using a server plugin we tried adding the OID from the IDToken to the claims.

However it appears that the claims are not exposed to the session object when using getUserSession on the server-side. We need a way to identify the user and OID is our current way to go.

Adding a way to expose claims to the serverside session would be ideal.