Give a try to parametrized tests for round-trip tests

[mathbagu]

• Do you want to request a feature or report a bug?
  Refactoring

• What is the current behavior?
  The support of different version of XIIDM or extensions is tested manually, duplicating code in the test.

• If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem

• What is the expected behavior?
  A better way to implement this is to use parametrized test.

• What is the motivation / use case for changing the behavior?
  Have less code to maintain and make it faster to test a new XIIDM version

• Please tell us about your environment:

  • PowSyBl Version: ...
  • OS Version: ...

• Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. stackoverflow, spectrum, etc)

(if a question doesn't apply, you can delete it)