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
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.
