Add scroll bar to search result list

Enhancement request.

When there's not much chat – not much apparent in search results – the absence of a scroll bar can be a minor annoyance.

The longer I spent in a recently-created set of rooms, the greater the frustration when I was forced to move from one result to another, without a scroll bar, without knowing when the list might end.

I see that it isn't visible on the clouds(purple) left menu.

The scroll bar has returned on our light theme revamp on next, just very light at the moment.