[Federation] Policy operators: The grant_types metadata is a JSON array, use scope as example instead

[Vladimir Dzhuvinov]

In the current draft 27:

https://openid.net/specs/openid-connect-federation-1_0.html#name-operators

Note that when a parameter is defined as a space-separated list of strings like for grant_types in [RFC7591] subset_of, superset_of and default are still expressed as lists of strings.

We should have this instead:

Note that when a parameter is defined as a space-separated list of strings, like scope in [RFC7591], the default, subset_of and superset_of policies are still expressed as JSON arrays of strings.

This issue is related to #1837.

https://bitbucket.org/openid/connect/issues/1837/federation-metadata-policy-relying-party

‌

[Giuseppe De Marco]

Fixed here
https://bitbucket.org/openid/connect/pull-requests/458#Lopenid-connect-federation-1_0.xmlF1477T1502
This is a regression caused by a previous commit, thank you

[Giuseppe De Marco]

Closed by PR 458