Add Event system

- Add abstract Event class
- Add EventDispatcher
- Add Mouse, Key and Window Events

CopiumEngine/src/copium/event/KeyPressEvent.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#include "copium/event/Event.h"
+
+namespace Copium
+{
+  class KeyPressEvent : public Event
+  {
+  private:
+    int button;
+  public:
+    KeyPressEvent(int button);
+
+    int GetButton() const;
+  };
+}