Fix RangeError invalid timestamp

ts/util/formatTimestamp.ts

@@ -0,0 +1,17 @@
+// Copyright 2023 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assertDev } from './assert';
+
+export function formatTimestamp(
+  timestamp: number,
+  options: Intl.DateTimeFormatOptions
+): string {
+  const locale = window.getPreferredSystemLocales();
+  try {
+    return new Intl.DateTimeFormat(locale, options).format(timestamp);
+  } catch (err) {
+    assertDev(false, 'invalid timestamp');
+    return '';
+  }
+}