add EntityAdmin wrapper

src/lib/core/EntityAdmin.cpp

@@ -0,0 +1,33 @@
+#include "EntityAdmin.h"
+
+std::shared_ptr<EntityAdmin> EntityAdmin::getInstance()
+{
+	if (!s_instance)
+	{
+		s_instance = std::shared_ptr<EntityAdmin>(new EntityAdmin());
+	}
+	return s_instance;
+}
+
+std::shared_ptr<EntityAdmin> EntityAdmin::s_instance;
+
+bool EntityAdmin::isValid(const entt::entity &entity)
+{
+	return m_registry->valid(entity);
+}
+
+void EntityAdmin::clear()
+{
+	m_registry->clear();
+}
+
+void EntityAdmin::destroy(entt::entity &entity)
+{
+	m_registry->destroy(entity);
+}
+
+EntityAdmin::EntityAdmin()
+	: m_registry(std::make_shared<entt::registry>())
+{
+}
+