- load more messages on scroll up for chat/channel added
- sending messages improved in terms of adding new messages to
appropriate position
- scroll to message added on the qml side
- qml connected to the sending message success/failed signals
- `chatType` added to `Constants` to group chat type related values
- `messageContentType` added to `Constants` to group message content type related
values
- `MessageStore` maintained per message list now
- added new `ChatContentView` component used to display chat/channel content
- components updated to display messages from the new backend
- `StatusChatToolBar` appropriately updated
- mute/unmute feature added to chat/channel list as well as to `StatusChatToolBar`