Support new action invocation status.

[Thisara-Welmilla]

Issue:

• Improve action execution core to support for INCOMPLETE state wso2/product-is#22165

With this PR, the following improvement is incorporated into the action execution core:

• A new INCOMPLETE action invocation status is introduced with Improve action execution core wso2/carbon-identity-framework#6262. This PR overrides the processIncompleteResponse(Map<String, Object> eventContext, Event actionEvent, ActionInvocationIncompleteResponse incompleteResponse) method in the ActionExecutionStatus class. Within this method, an UnsupportedOperationException is thrown because the INCOMPLETE state is not acceptable for pre-issue access tokens.