Make sure that a `MessageDelegateBase` is not used after free by a `MessageObjectIncubator` callback by tracking them and cleaning them up on deletion of a `MessageDelegateBase`
Refactor TimelineView to make it more reliable and prepare for read marker choice. This is done by creating signalling from the mode when reset which can be used to move the scrollbar to the newest meassage.
Some of the spaghetti is also removed so there is no need for ChatBar and TimelineView to talk directly.
The code to mark messages as read if they are all visible after 10s has been removed infour of just marking as read on entry if all are visible. This is temporary until a follow up providing user options is finished (although it will be one of the options)
Replace HoverActions with an inline action component that appears on hover. There are only actions for reply and react if there is space the overflow button opens the normal message menu.
NOTE: the most recent update changes things slightly, from the images below the buttons are now top aligned because of potentially hige messages. The actions are also now disabled for compact mode as they never really made sense there anyway. The menu now has all options so no one is missing out.
For normal messages
{width=419 height=138}
When space is limited
{width=411 height=130}
User messages
{width=296 height=114}
BUG: 503784
This should be set *before* we clean up the incubator, because it could
end up accessing invalid data when the incubator is freed. This fixes a
regularly occuring crash when switching rooms.
Rework MessageDelegate to be mostly a cpp class. This allows us to only load the components that are actually needed saving memory.
In testing using memtest it saved ~30% versus the current implementation.
