Open all links in a new tab (#4582)

### What
* Closes #4105

### Checklist
* [x] I have read and agree to [Contributor
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 newly built examples:
[app.rerun.io](https://app.rerun.io/pr/4582/index.html)
* Using examples from latest `main` build:
[app.rerun.io](https://app.rerun.io/pr/4582/index.html?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[app.rerun.io](https://app.rerun.io/pr/4582/index.html?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG

- [PR Build Summary](https://build.rerun.io/pr/4582)
- [Docs
preview](https://rerun.io/preview/e750f29d2359e8522dccba97274e6a9de47a3828/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/e750f29d2359e8522dccba97274e6a9de47a3828/examples)
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- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

crates/re_viewer/src/app.rs

@@ -1170,6 +1170,13 @@ impl eframe::App for App {
             }
         });
 
+        egui_ctx.output_mut(|o| {
+            // Open all links in a new tab (https://github.com/rerun-io/rerun/issues/4105)
+            if let Some(open_url) = &mut o.open_url {
+                open_url.new_tab = true;
+            }
+        });
+
         // Frame time measurer - must be last
         self.frame_time_history.add(
             egui_ctx.input(|i| i.time),