Fix Chat Room Bugs When Changing Rooms and in Direct Messages

[mariobehling]

Objective:
Address and resolve bugs related to changing chat rooms and handling direct messages to ensure a seamless user experience.

Tasks:

1. Reset Message Fetching When Changing Rooms

   • Ensure that message fetching is properly reset when a user switches between chat rooms.

2. Notification Handling in Volatile Channels

   • Prevent notifications for messages that have already been read in volatile channels.
   • Ensure that notifications are only triggered for new, unread messages.

3. Fix Direct Messages Notification Exception

   • Resolve the exception issue that occurs with direct message notifications.

4. Fix Presentation Slides and Slide Interval