LibWeb: Fire a change event on input elements in the focus update steps

This ensures the change event is received before the blur event.

Tests/LibWeb/Text/input/input-commit-on-unfocus.html

@@ -0,0 +1,18 @@
+<input id=input type=text>
+<script src="include.js"></script>
+<script>
+    test(() => {
+        let input = document.getElementById("input");
+
+        input.addEventListener("change", () => {
+            println(input.value);
+        });
+
+        input.addEventListener("blur", () => {
+            println("blur");
+        });
+
+        internals.sendText(input, "wfh :^)");
+        input.blur();
+    })
+</script>