DRY up the message receive timing validation

ts/util/isTooOldToModifyMessage.ts

@@ -0,0 +1,14 @@
+// Copyright 2023 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import type { MessageAttributesType } from '../model-types.d';
+import { DAY } from './durations';
+
+export function isTooOldToModifyMessage(
+  serverTimestamp: number,
+  message: MessageAttributesType
+): boolean {
+  const messageTimestamp = message.serverTimestamp || message.sent_at || 0;
+  const delta = Math.abs(serverTimestamp - messageTimestamp);
+  return delta > DAY * 2;
+}