First state of UI rewrite, reimplemenation of agent status displays

@abnanda1 @DamianEdwards @davidfowl @moozzyk 
In one of the branches off of this PR, this ends up moving into the "modelUpdateService" so that the logic is not duplicated. It also ends up being rolled into a loop that does other per-worker updates.
In theory, this could be done as an array.reduce call if we want to be explicit about it.