[Feature Request][WEBJS] - Unread chats features - events about changes, clear unread message counts

[meovary150]

I would like the ability to:

1. Receive notifications or events when the unread message count changes.
2. Clear the unread message counts programmatically.

~~3. Send contact cards via the API.~~ - moved to https://github.com/devlikeapro/waha/issues/430