Added Smart Highlighting for mapped workspaces. (#288)

* Improved workspace highlighting and added smart highlight option

* Added to default workspace variant.

* Remove hover effects

* Remove unused functions.

* Remove unused hover properties

* Remove unused variable from utils.

* Make hideUnoccupied the default option

scss/style/bar/notifications.scss

@@ -27,6 +27,7 @@
             $bar-buttons-radius * 0.4,
             $bar-buttons-radius
         );
+        color: if($bar-buttons-monochrome, $bar-buttons-icon, $bar-buttons-notifications-icon);
     }
 
     .bar-button-label.notifications {