Dismiss ExternalNotification nagging on InkHUD button press (#7056)

* Expose ExternalNotification::isNagging

* Dismiss external notification on button press

src/modules/ExternalNotificationModule.cpp

@@ -293,6 +293,12 @@ bool ExternalNotificationModule::getExternal(uint8_t index)
     return externalCurrentState[index];
 }
 
+// Allow other firmware components to determine whether a notification is ongoing
+bool ExternalNotificationModule::nagging()
+{
+    return isNagging;
+}
+
 void ExternalNotificationModule::stopNow()
 {
     rtttl::stop();