Don't use std::shared_ptr to store m_ScriptContext and m_ScriptInterface in the CGUIManager

`std::shared_ptr` is intrusive. When a function expects a
`std::shared_ptr` the caller has to use it too and can't store the
element on the stack for example.

Comments by: @vladislavbelov
Differential Revision: https://code.wildfiregames.com/D5221
This was SVN commit r28131.

source/main.cpp

@@ -678,9 +678,12 @@ static void RunGameOrAtlas(const PS::span<const char* const> argv)
 			g_Mods.UpdateAvailableMods(modInterface);
 		}
 
+		std::optional<ScriptInterface> guiScriptInterface;
+
 		if (isVisual)
 		{
-			InitGraphics(args, 0, installedMods);
+			guiScriptInterface.emplace("Engine", "gui", *g_ScriptContext);
+			InitGraphics(args, 0, installedMods, *g_ScriptContext, *guiScriptInterface);
 			MainControllerInit();
 		}
 		else if (!InitNonVisual(args))
@@ -709,6 +712,7 @@ static void RunGameOrAtlas(const PS::span<const char* const> argv)
 		modsToInstall.clear();
 
 		ShutdownNetworkAndUI();
+		guiScriptInterface.reset();
 		ShutdownConfigAndSubsequent();
 		MainControllerShutdown();
 		flags &= ~INIT_MODS;