Implement scope model to support identity and resource scopes

[leastprivilege]

brain dump:

possible scopes:

openid
response: code
return return code for id token, access token with scope: openid
response: id_token
return minimal id token
response: id_token token
return minimal id token, access token with scope: openid
response: token
error

openid profile
response: code
return return code for id token, access token with scope: openid profile
response: id_token
return id token with profile
response: id_token / post
return (== post) id token with profile
response: id_token token
return minimal id token, access token with scope: openid profile
response: token
error

openid profile resource
response: code
return return code for minimal id token, access token with scope: openid profile resource
response: id_token
error
response: id_token token
return minimal id token, access token with scope: openid profile resource
response: token
error

openid resource
response: code
return return code for minimal id token, access token with scope: openid resource
response: id_token
error
response: id_token token
return minimal id token, access token with scope: openid resource
response: token
error

resource
response: code
return return code for access token with scope: resource
response: id_token
error
response: id_token token
error
response: token
return access token with scope: resource

[leastprivilege]

or per response type:

er response type:

code
id
resource

id_token
id

id_token token
id
resource

token
resource

[leastprivilege]

prototype done d4095aa