Refactor alarm system and replace notification method

The old OpenVR overlays did not function for unknown reasons, and it was
not possible to get them to work.

With this a white overlay with ALARM ACTIVATED will be shown for 3 seconds.
It's not pretty, but it effectively communicates that an alarm has been
activated.

This fixes
https://github.com/OpenVR-Advanced-Settings/OpenVR-AdvancedSettings/issues/417

src/overlaycontroller.h

@@ -1,4 +1,3 @@
-
 #pragma once
 
 #include <openvr.h>
@@ -43,6 +42,8 @@
 
 #include "openvr/ivrinput.h"
 
+#include "alarm_clock/vr_alarm.h"
+
 namespace application_strings
 {
 constexpr auto applicationOrganizationName = "AdvancedSettings-Team";
@@ -152,6 +153,8 @@ private:
 
     input::SteamIVRInput m_actions;
 
+    alarm_clock::VrAlarm m_alarm;
+
     QNetworkAccessManager* netManager = new QNetworkAccessManager( this );
     QJsonDocument m_remoteVersionJsonDocument = QJsonDocument();
     QJsonObject m_remoteVersionJsonObject;