Fault trees do not always get refreshed

[reteprelief]

Resource URI in SiriusUtil is set wrong which prevents loading proper representation from aird file.

EcoreUtil appends suffix to resource URI that prevents loading proper resource later. This means that on model updates (say constants in aadl file) we'll keep showing original representation with old values and the only way to bypass this is to delete representations.aird file. With this update it will be enough to just instantiate model.