Fix search editor scrolled to bottom on first search when editor group changed.

[ssigwart]

This PR fixes #134686

I'm not sure it's the best solution, but this solves it.

[JacksonKearl]

Thanks! Looking into this it seems the real culprit was failing to await the write of the results to the model before setting the view's scroll position, which meant when the contents did come in it tried to insert them "before" the existing scroll position, resulting in the document scrolling to the bottom. It's not clear to me why this only affected editors after they've been moved, perhaps something to do with the view state being stored on a per-group basis.

[ssigwart]

Thanks. That's a much cleaner solution!