Window within window scrolling

[peth-yursick]

Another one surfaced by user testing was this "scroll inside a window inside a scrollable window" thing.

You can see in some of the longer answers, you get a scrollbar.

Instead of this happening, the whole page should be scrollable.
Also maybe the whole text should be appearing a bit higher, which would already fix the issue in most cases.
This should probably be implemented before #1664