Lab VM: Notifications now bind to CollectionChanged instead of buttons.
Lab: Bug fixes. (...)

- Fixed lab tests to fit with new denomination and default loaded state.
- If a selected plugin/service is deleted from outside the VM, it will now be deselected.
- Removed IsLive property from ViewModel; use ViewModel.LabState.Engine.IsRunning instead.
- Added bool IsRunning to IYodiiEngine interface.