Behaviour Change in Access Tokens issued for authenticated applications

[SujanSanjula96]

Describe the issue:
Following two behavioural changes are done for the access tokens issuing for authenticated applications using a grant type like client credentials.

• sub claim of the jwt tokens issued for authenticated application is set as client id of the authenticated application. (Previous behaviour - sub claim is set as the user ID of the application owner)
• Username field is removed from the introspection response for access tokens issued for authenticated applications.

To keep the backward compatibility, we have introduced two configurations. Two configurations can be set to false for the previous behaviour.

[oauth]
use_client_id_as_sub_claim_for_app_tokens = false
remove_username_from_introspection_response_for_app_tokens = false

Related issues:
#14771

Related PRs:
wso2/carbon-identity-framework#4633
wso2-extensions/identity-inbound-auth-oauth#2088

[melanisilva]

Verified

IS Pack - WSO2 Identity Server-7.0.0-m4-SNAPSHOT