* fix wechat issues:
1. change table msg type to markdown.
2. change userId to not required and enrich hints
3. change 'app id' to 'app id and chat id'
* fix wechat issues:
1. revert table showtype and add markdown showtype.
2. enrich hints.
3. delete 'chatid', rename agentid to weChatAgentIdChatId.
4. modify code to send markdown message.
* fix wechat issues: Change the language pack of agentId to agentId/chatId.
* fix format
* fix param name
Co-authored-by: Amy <amywang0104@163.com>