refs #538, Formatting, minor tweaks, comments

* new slot syntax in ATC station component
* formatting, comments
* tab order
* utility function for severity in status message
* null checks in threadutils
* invalidKey function in datastore
* changed data object keys (cached objets)
* added missing value object compare cases
* renamed timer in context network
* finder function for model list
* renamed getContainer to container (as it is just a reference)

src/blackgui/views/atcstationview.h

@@ -27,7 +27,6 @@ namespace BlackGui
             Q_OBJECT
 
         public:
-
             //! Constructor
             explicit CAtcStationView(QWidget *parent = nullptr);