Added setting for opening streams from toast

Implemented #710

Added options for opening streams from clicking the toas notficiation: (according to options in splits)
- open in browser
- open player in browser
- open in streamlink (needs to be tested, but should in theory work, since I only use the already existing function)
- don't open the stream (in case someone wants to prevent opening streams "by accident")

src/singletons/Settings.hpp

@@ -172,6 +172,7 @@ public:
                                             "qrc:/sounds/ping3.wav"};
 
     BoolSetting notificationToast = {"/notifications/enableToast", false};
+    QStringSetting openFromToast = {"/notifications/openFromToast", "in browser"};
 
     /// External tools
     // Streamlink