Ajouts d'une premiere version du chargement des donnees test

res/stages/main-stage.fxml

src/main/java/fr/univlille/sae/classification/Main.java

...lle/sae/classification/controller/LoadDataController.java

...le/sae/classification/controller/MainStageController.java

...ivlille/sae/classification/model/ClassificationModel.java

...va/fr/univlille/sae/classification/view/LoadDataView.java

...a/fr/univlille/sae/classification/view/MainStageView.java