Smooth scrolling in 2D space views (#6422)

When scrolling with a discreet mouse wheel, the scrolling is now
smoothed.

### Checklist
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Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using examples from latest `main` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/6422?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/6422?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
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checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!

- [PR Build Summary](https://build.rerun.io/pr/6422)
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
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crates/re_space_view_spatial/src/ui_2d.rs

@@ -80,12 +80,7 @@ fn ui_from_scene(
 
  let mut pan_delta_in_ui = response.drag_delta();
  if response.hovered() {
- // NOTE: we use `raw_scroll` instead of `smooth_scroll_delta` to avoid the
- // added latency of smoothing, which is really annoying on Mac trackpads.
- // The smoothing is only useful for users with discreet scroll wheels,
- // and they are likely to pan with dragging instead.
- // TODO(egui#4401): https://github.com/emilk/egui/issues/4401
- pan_delta_in_ui += response.ctx.input(|i| i.raw_scroll_delta);
+ pan_delta_in_ui += response.ctx.input(|i| i.smooth_scroll_delta);
  }
  if pan_delta_in_ui != Vec2::ZERO {
  *visual_bounds =