Exercise 7 - Classification: Add Calculation and Plotting of ROC Curve

[melsigl]

Add exercise to calculate ROC curve table and then plot ROC curve. Similar to figures 8.18 and 8.19 in the 3rd edition of the book.

[dominik-probst]

Even though the exercises in the summer semester 2024 were fundamentally revised, such a calculation would still find a place on the classification exercise sheet.

However, the new classification exercise sheet is already on a tight schedule, so this should be carefully considered.

For now, the issue remains open but postponed.