Error message : Invalid scenario name in data_file

[TOP-PHE]

If the end user is configuring an invalid scenario name in his data_file, the scenario runs anyway but with unpredictable results... Difficult for the end iuser to find teh origin of the issue.
We shoudlm checkk the scenario name is in the postmane scenario list. If not we should stop the scenario with an error message
Maybe to ease the end user life also provide him in the error message the list of vailable scenarios he can use.