Add led indicator setting, use one setting for notifications, move it under general

include/LedIndicator.hpp

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <X11/Xlib.h>
+#include <mglpp/system/Clock.hpp>
+
+namespace gsr {
+    class LedIndicator {
+    public:
+        LedIndicator(Display *dpy);
+        LedIndicator(const LedIndicator&) = delete;
+        LedIndicator& operator=(const LedIndicator&) = delete;
+        ~LedIndicator();
+
+        void set_led(bool enabled);
+        void blink();
+        void update();
+    private:
+        void update_led(bool new_state);
+    private:
+        Display *dpy = nullptr;
+        Atom scroll_lock_atom = None;
+        bool led_indicator_on = false;
+        bool led_enabled = false;
+        bool perform_blink = false;
+        mgl::Clock blink_timer;
+    };
+}