UX improvements for Model Online Prediction Result Table

[amadr]

• Change wording of online prediction button to "Add Test Dataset"
• Adjust the heading to "Predictions (20 sample rows)" and add tooltip
• Add an "Index" column header
• Format the table, add a line between columns
• Add hover tooltip to download button

• 513

[AlexanderZender]

When you click on a predicted test dataset, the frontend crashes. The log:

[amadr]

@AlexanderZender Which Dataset are you using? I think the issues seems to be that there is no "Outcome" column after the prediction. I have no problems with the diabetes dataset. Nevertheless, I changed the code so now we should not get a IndexOutOfRangeException.