LogSetupInformation in CreateInstance is too invasive

I think the LogSetupInformation was too invasive in Logger::CreateInstance(). For instance, just printing the help of an otbcli application, you get those 3 lines of logs just before the list of parameters (plus, they are useless here since no processing is done). I moved it to 2 locations:

• in the TestMain, just before launching the test
• in otb::Wrapper::Application, at the start of ExecuteAndWriteOutput() (and it allows also to use the application own logger directly instead of the singleton).

Feel free to suggest other relevant places.