Improve the opening bracket preview
- If the bracket is on a single line by itself, use the full width of the line directly above to maximize the shown context
- Use 2 lines instead of 3 to make the preview more compact and easier to understand (e.g. in case of nested if blocks)
- Do not show preview when it will cover the cursor or during scroll
- Make sure the preview is hidden when the view changes and that it does not overextend outside the view/window