move code from Diagnostics and Guard to cpp

src/core/Guard.cpp

@@ -0,0 +1,24 @@
+#include <cassert>
+#include <stdio.h>
+
+#include "Console.hpp"
+#include "Diagnostics.hpp"
+#include "Guard.hpp"
+
+namespace Guard
+{
+    void Assert(bool expression, const char * message)
+    {
+        if (expression) return;
+
+        if (message != nullptr)
+        {
+            Console::Error::WriteLine(message);
+        }
+
+#if DEBUG
+        Debug::Break();
+#endif
+        assert(false);
+    }
+}