Forum: improve new entry highlighting
New forum entries are currently only highlighted, with direct scrolling via the snack bar, when the user already has the respective forum screen visible. A user got a new forum entry notification for a forum with a lot of entries, opened the forum but had no idea where the new forum entry was due to the non-linear nature of the forums.
This is simple in private messaging because the latest entries are almost always at the bottom but we really need to show the user better what forum entries he hasn't read yet.