Implemented requested changes

changed setting from String to int.
changed EnumCase

I used createComboBox only has an implementation that handles stringsettings. I implemented my own combobox to handle the ToastsSettings now. Not sure if this is the best way. Won't come up with something smarter for now.

src/widgets/settingspages/NotificationPage.hpp

@@ -15,6 +15,8 @@ public:
     NotificationPage();
 
 private:
+    QComboBox *createToastReactionComboBox(
+        std::vector<pajlada::Signals::ScopedConnection> managedConnections);
 };
 
 }  // namespace chatterino