fix: add property fallback for WID objects and update loadEarlierMsg…

[Rajojha-1]

Description

Fixes the minified r: r crash and TypeError when calling getChat(), getChatById(), or chat.fetchMessages().

WhatsApp Web's July 2026 update renamed internal WID serialized properties from _serialized to $1 and updated WAWebChatLoadMessages.loadEarlierMsgs parameter handling.

This PR:

1. Adds Base._normalizeId(id) in src/structures/Base.js to ensure _serialized falls back to $1 without mutating original keys or breaking E2E decryption.
2. Updates Message.js (from, to, author) and Utils.js (getMessageModel, getChat) to handle $1 property fallbacks.
3. Updates Chat.prototype.fetchMessages to pass searchOptions into loadEarlierMsgs.

Related Issue(s)

fixes #201838
resolves #201849
resolves #201862
resolves #201869

Testing Summary

Test Details

• Tested chat.fetchMessages({ limit: 50 }) on 1-on-1 contact chats and group chats.
• Verified _serialized property fallback prevents r: r minified errors.
• Verified historical messages load without throwing TypeError.

Environment

• Machine OS: Windows 11
• Phone OS: Android / iOS
• Library Version: 1.34.7
• WhatsApp Web Version: 2.3000.1017054665
• Browser Type and Version: Chromium / Puppeteer
• Node Version: v20.x

Type of Change

• Bug fix (non-breaking change that fixes an issue)

Checklist

• My code follows the style guidelines of this project.
• All new and existing tests pass (npm test).