SPEC-7531 Change Code/CryEngine to Code/Legacy (#1634)

* git mv Code\CryEngine Code\Legacy
* redirecting CMakeLists.txt
* fixing uic warning
* Some more CryEngine mentions
* validation scripts

Signed-off-by: Esteban Papp <81431996+amznestebanpapp@users.noreply.github.com>

Code/Legacy/CryCommon/IWindowMessageHandler.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project
+ * 
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+
+#ifndef _CRY_WINDOW_MESSAGE_HANDLER_H_
+#define _CRY_WINDOW_MESSAGE_HANDLER_H_
+#include "platform.h"
+#if defined(WIN32)
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif
+#include <windows.h>
+
+// Summary:
+//      Window message handler for Windows OS
+struct IWindowMessageHandler
+{
+    // Summary:
+    //      The low-level pre-process message handler for Windows
+    //      This is called before TranslateMessage/DispatchMessage (which will eventually end up in the HandleMessage handler)
+    //      Typically, do not implement this function.
+    virtual void PreprocessMessage([[maybe_unused]] HWND hWnd, [[maybe_unused]] UINT uMsg, [[maybe_unused]] WPARAM wParam, [[maybe_unused]] LPARAM lParam) {}
+
+    // Summary:
+    //      The low-level window message handler for Windows
+    //      The return value specifies if the implementation wants to modify the message handling result
+    //      When returning true, the desired result value should be written through the pResult pointer
+    //      When returning false, the value stored through pResult (if any) is ignored
+    //      If more than one implementation write different results, the behavior is undefined
+    //      If none of the implementations write any result, the default OS result will be used instead
+    //      In general, return false if the handler doesn't care about the message, or only uses it for informational purposes
+    virtual bool HandleMessage([[maybe_unused]] HWND hWnd, [[maybe_unused]] UINT uMsg, [[maybe_unused]] WPARAM wParam, [[maybe_unused]] LPARAM lParam, [[maybe_unused]] LRESULT* pResult) { return false; }
+};
+#else
+// Summary:
+//      Dummy window message handler
+//      This is used for platforms that don't use window message handlers
+struct IWindowMessageHandler
+{
+};
+#endif
+#endif