Switch from events to setting service flags.

Instead of firing events on the topology, we're switching to setting
flags on the service and unit models in the DB. That way the data is
persistent across state changes (i.e., when a user switches from
service view to machine view) and we maintain one single source of
truth.
Machine tokens are correctly shown/hidden when the user modifies the triggers in the added services sidebar
Unit token rendering now correctly respects when units have been highlighted, hiding the others
Fix toggling between states.
Only allow one service to be highlighted at a time.
Merge pull request #631 from kadams54/added-services-db-refactor-2

Switch from events to setting service flags.

Instead of firing events on the topology, we're switching to setting
flags on the service and unit models in the DB. That way the data is
persistent across state changes (i.e., when a user switches from
service view to machine view) and we maintain one single source of
truth.
Merge pull request #633 from kadams54/toggle-highlight

Only allow one service to be highlighted at a time.