postal_code/etc in address claim should be stated to be strings

Issue #2047 resolved
Joseph Heenan created an issue

https://openid.net/specs/openid-connect-core-1_0.html#AddressClaim doesn’t define the types for the members. It should state that they are all strings. (I don’t think there’s any real ambiguity, except for postal_code which is purely numeric in some countries.)