Implement Set, Refactor Map into Tree

tests/Engine/System/CMakeLists.txt

@@ -0,0 +1,3 @@
+target_sources(SeeleUnitTests
+	PRIVATE
+		ComponentSystem.cpp)

tests/Engine/System/ComponentSystem.cpp

@@ -0,0 +1,9 @@
+#include "EngineTest.h"
+#include "Component/Component.h"
+#include "Component/Transform.h"
+#include "Component/Camera.h"
+#include "Component/DirectionalLight.h"
+#include "System/ComponentSystem.h"
+
+using namespace Seele;
+using namespace Seele::System;