bug: pinned messages in large sessions navigate incorrectly

[MCBoarder289]

I noticed that pinned messages on large sessions with many messages don't navigate properly via the link to open the session to that message. I've had to play around with sort order to get the pinned message navigation to work somewhat, but it often doesn't scroll to the right position.

I've worked up a branch resolve this and will link to the PR. My suspicion is that has to do with the scrolling behavior.

[MCBoarder289]

This is kind of hard to reproduce, but how I reproduced locally on my machine was pinning one of the most recent messages in a long session with lots of messages. If I was using the default sort order, it would just stay at the top when I tried to navigate via the pinned message pane. If I used reverse sort order, it would get close, but often not exact and I'd have to do some more scrolling.

[MCBoarder289]

Closing this issue as it's mostly resolved. I did open a new issue (#241) to address some edge case behavior, but this issue is at least resolved and works extremely well when ordering messages in descending order.