This is a non-issue, because it is already implemented. Click on the arrow keys and it will be toggled. However, if you have both arrow panels on the wheels, be warned there's a minor bug that can give you a headache from your rover not stopping. Make sure to only use the left pad or the right pad only. Otherwise it might be triggered and you have to fiddle with both until it'll stop.

Already possible using the GUI forward button :)