refactor: removed MainFXMLController from dependencies

Replaced MainFXMLController-based scene-changing with event-based scene-changing to remove cyclic dependency

src/main/java/ch/zhaw/gartenverwaltung/MyGardenController.java

@@ -2,6 +2,7 @@ package ch.zhaw.gartenverwaltung;
 
 import ch.zhaw.gartenverwaltung.bootstrap.AfterInject;
 import ch.zhaw.gartenverwaltung.bootstrap.AppLoader;
+import ch.zhaw.gartenverwaltung.bootstrap.ChangeViewEvent;
 import ch.zhaw.gartenverwaltung.bootstrap.Inject;
 import ch.zhaw.gartenverwaltung.io.PlantList;
 import ch.zhaw.gartenverwaltung.models.Garden;
@@ -17,6 +18,7 @@ import javafx.scene.control.Button;
 import javafx.scene.control.ButtonType;
 import javafx.scene.control.Label;
 import javafx.scene.image.ImageView;
+import javafx.scene.layout.AnchorPane;
 import javafx.scene.layout.HBox;
 import javafx.scene.layout.Priority;
 import javafx.scene.layout.VBox;
@@ -30,16 +32,15 @@ import java.util.logging.Logger;
 
 public class MyGardenController {
     private static final Logger LOG = Logger.getLogger(MyGardenController.class.getName());
-
     @Inject
     AppLoader appLoader;
     @Inject
-    MainFXMLController mainController;
-    @Inject
     private Garden garden;
     @Inject
     private PlantList plantList;
 
+    @FXML
+    public AnchorPane myGardenRoot;
     @FXML
     private VBox myPlants_vbox;
 
@@ -61,8 +62,8 @@ public class MyGardenController {
     }
 
     @FXML
-    void addPlant(ActionEvent event) throws IOException {
-        mainController.showPaneAsMainView("Plants.fxml");
+    void addPlant() {
+        myGardenRoot.fireEvent(new ChangeViewEvent(ChangeViewEvent.CHANGE_MAIN_VIEW, "Plants.fxml"));
     }
 
     private void createPlantView(List<Crop> crops) throws HardinessZoneNotSetException, IOException {