System level top-bar

[Eeems]

• System service should handle displaying top-bar
• Application registration flag to enable system level top-bar being displayed
• top-bar should be it's own surface that can be overridden just like the notification and system overlays
• Top bar should include/replace the following features from the launcher/lockscreen:
  • Date/time
  • Battery level
  • wifi state
  • notifications
  • button to open power menu in system overlay
  • Calendar popup
  • notification menu popup
  • wifi menu popup