A few minor UI tweaks and fixes.

1. Use system menu bar on macOS, there's no reason to make the user to set apple.laf.useScreenMenuBar manually in a custom script.
2. Everything else uses sans font so AboutDialog should probably do that too.
3. GetScrollableUnitIncrement calculates the horizontal unit increment by column size, so horizontal scrolling is way too fast if you have only a few very wide columns. Override this to a sensible value.
4. The result table has some very bad flickering with auto search enabled, I've increased the debounce timer a little without making it feel sluggish.
5. The wrap-around behavior for tab scrolling is very annoying if you have a large list of tabs open. This could be made configurable but no other text editors or web browsers with tabs does this, it's probably easier to just disable it for now.