MINOR: jwt: jwt_header_query and jwt_payload_query converters

Those converters allow to extract a JSON value out of a JSON Web Token's
header part or payload part (the two first dot-separated base64url
encoded parts of a JWS in the Compact Serialization format).
They act as a json_query call on the corresponding decoded subpart when
given parameters, and they return the decoded JSON subpart when no
parameter is given.
3 files changed