crm,credential: repair Ticket_getWorkflowStateTranslatedTitle for ERP5 workflow

`state_var` is now a compatibility alias calling getStateVariable, which
has a default value of `simulation_state`. As a result, this script was
attempting to call getSimulationStateTranslatedTitle on credential
requests, because they have an interaction workflow in their chain.

This fixes by implementing the full logic using new ERP5 workflow API.
8 jobs for fix/state_var in 0 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-Master

00:50:46

passed ERP5.PerformanceTest-Master

00:27:03

failed ERP5.UnitTest-Master

01:52:35

failed ERP5.UnitTest-Zope2

02:54:29

passed SlapOS.Eggs.UnitTest-Master.Python2

00:14:59

passed SlapOS.Eggs.UnitTest-Master.Python3

00:15:54

passed Wendelin.UnitTest-Master

03:58:31

failed Wendelin.UnitTest-Master

00:27:28