id_token_signed_response missing

[Pamela Dingle]

Noted by Brian C:

id_token_signed_response_alg isn't in uk-openbanking-registration-profile.md anywhere but according to http://openid.net/specs/openid-connect-registration-1_0.html#ClientMetadata 'The default, if omitted, is RS256.' But OB doesn't want to allow use of RS256 (only ES and PS) so that default won't work.

[Pamela Dingle]

Added this metadata to the request chart and to examples. See commit: https://bitbucket.org/openid/obuk/commits/f5e5647c68a301b182eb0c84c1a34090ecbe629a