Tests/LibWeb: Add test for MouseEvent and WheelEvent bubbling

Author: https://github.com/circl-lastname
Commit: https://github.com/LadybirdBrowser/ladybird/commit/89531fb115
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/667
Issue: https://github.com/LadybirdBrowser/ladybird/issues/660
Reviewed-by: https://github.com/kalenikaliaksandr ✅

Tests/LibWeb/Text/expected/UIEvents/MouseEvent-bubbling.txt

@@ -0,0 +1 @@
+  PASS (did not hang)

Tests/LibWeb/Text/expected/UIEvents/WheelEvent-bubbling.txt

@@ -0,0 +1 @@
+  PASS (did not hang)

Tests/LibWeb/Text/input/UIEvents/MouseEvent-bubbling.html

@@ -0,0 +1,24 @@
+<script src="../include.js"></script>
+<style>
+    * { border: 1px solid black; }
+    .inner { width: 100px; height: 100px; }
+</style>
+<div class="outer"><div class="inner">
+<script>
+    asyncTest(done => {
+        let eventCount = 0;
+
+        function clickHandler() {
+            eventCount++;
+            if (eventCount == 2) {
+                println('PASS (did not hang)');
+                done();
+            }
+        }
+
+        document.querySelector('.outer').addEventListener('click', clickHandler);
+        document.querySelector('.inner').addEventListener('click', clickHandler);
+
+        internals.click(50, 50);
+    });
+</script>

Tests/LibWeb/Text/input/UIEvents/WheelEvent-bubbling.html

@@ -0,0 +1,24 @@
+<script src="../include.js"></script>
+<style>
+    * { border: 1px solid black; }
+    .inner { width: 100px; height: 100px; }
+</style>
+<div class="outer"><div class="inner">
+<script>
+    asyncTest(done => {
+        let eventCount = 0;
+
+        function wheelHandler() {
+            eventCount++;
+            if (eventCount == 2) {
+                println('PASS (did not hang)');
+                done();
+            }
+        }
+
+        document.querySelector('.outer').addEventListener('wheel', wheelHandler);
+        document.querySelector('.inner').addEventListener('wheel', wheelHandler);
+
+        internals.wheel(50, 50, 10, 0);
+    });
+</script>