Add a "line wrap" switch to the serial monitor

In the new IDE the serial monitor has changed from a resizable window to a tab - when I want to see a complete line in the serial monitor that is longer than the size of the IDE I have to enlarge the whole IDE window.

**Describe the solution you'd like**
Add a "line wrap" switch to the serial monitor, so that a whole line can be seen regardless of the main window size.
