Add underline effect to clickable notification labels (#3757)

src/main/resources/css/dark_theme.css

@@ -359,6 +359,12 @@
 	-fx-background-color: PRIMARY;
 }
 
+.notification-debug:hover .notification-label,
+.notification-update:hover .notification-label,
+.notification-support:hover .notification-label {
+ 	-fx-underline:true;
+}
+
 /*******************************************************************************
  *                                                                             *
  * ScrollBar                                                                   *

src/main/resources/css/light_theme.css

@@ -358,6 +358,12 @@
 	-fx-background-color: PRIMARY;
 }
 
+.notification-debug:hover .notification-label,
+.notification-update:hover .notification-label,
+.notification-support:hover .notification-label {
+	-fx-underline:true;
+}
+
 /*******************************************************************************
  *                                                                             *
  * ScrollBar                                                                   *