ImGuizmo: Fix crash at exit due to global context.

3rdparty/dear-imgui/widgets/gizmo.h

@@ -126,6 +126,12 @@ namespace IMGUIZMO_NAMESPACE
    // call BeginFrame right after ImGui_XXXX_NewFrame();
    IMGUI_API void BeginFrame();
 
+   //
+   IMGUI_API void Create();
+
+   //
+   IMGUI_API void Destroy();
+
    // this is necessary because when imguizmo is compiled into a dll, and imgui into another
    // globals are not shared between them.
    // More details at https://stackoverflow.com/questions/19373061/what-happens-to-global-and-static-variables-in-a-shared-library-when-it-is-dynam