BS-8754 : [6.3] Uncertain state for a task of a sub-event process

- The connector is put in FAILED state, after throwing the error event.
- Refactor tests
- Add new test : processWithErrorEventSubProcAndCallActivity_must_be_finished_when_subProcess_is_finished
- Add more verifications on test : connectorThatThrowExceptionErrorEventPolicyCallActivityOnTask