Added set Current Dataset Function

src/main/java/seng202/group9/Controller/App.java

@@ -182,6 +182,22 @@ public class App extends Application
 		return currentDataset;
 	}
 
+	/**
+	 * Sets the current Dataset to another Dataset by its index in the datasets arraylist
+	 * @param index
+     */
+	public void setCurrentDataset(int index){
+		currentDataset = datasets.get(index);
+	}
+
+	/**
+	 * Sets the current Dataset to another Dataset.
+	 * @param dataset
+     */
+	public void setCurrentDataset(Dataset dataset){
+		currentDataset = dataset;
+	}
+
 	/**
 	 * Creates new dataset.
 	 * @param datasetName