Fix React hydration issues (#32958)

* Add more playwright axe tests to settings dialogs

* Add utility to jest setupTests to detect React hydration errors

* Iterate jest utility

* Fix axe issue heading-order

* Fix div-in-p issues

* Fix setupTests.ts

* Fix heading order

* Make types happier

* Fix hydration issues of thead containing text nodes

* Update tests

* Fix form-in-form React hydration issues

* Fix li-in-li React hydration issues

* Fix checked in form without onChange React hydration issue

* Fix styling bleeding from _common.pcss

* Update snapshots

* Fix more remaining issues

* Remove _common.pcss h2 rule altogether

* Fix test

* Update snapshots

* Iterate

* Iterate

* Update snapshots

* Simplify diff

* Test

* Update screenshots

* Update screenshot

apps/web/src/utils/form.ts

@@ -0,0 +1,17 @@
+/*
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import type React from "react";
+
+/**
+ * onSubmit handler which calls preventDefault and stopPropagation on the event
+ * @param e submit event
+ */
+export function onSubmitPreventDefault(e: SubmitEvent | React.SubmitEvent): void {
+    e.preventDefault();
+    e.stopPropagation();
+}