Gallery expanded view description area needs to be scrollable if text doesn't fit

[misaugstad]

Brief description of problem/feature

You can see in this screenshot that if a lot of text is written in the description box, the text doesn't fit and overflows.

Potential solution(s)

Let's just set it to become scrollable if the text doesn't fit. If the text does fit, however, we should make sure that no scroll bar is visible.