Fix a few bugs related to the cheat panel

arm9/source/cheats/EmptyCheatRepository.h

@@ -0,0 +1,16 @@
+#pragma once
+#include "ICheatRepository.h"
+
+class EmptyCheatRepository : public ICheatRepository
+{
+public:
+    std::unique_ptr<GameCheats> GetCheatsForGame(const FastFileRef& romFile) const override
+    {
+        return nullptr;
+    }
+
+    void UpdateEnabledCheatsForGame(const std::unique_ptr<GameCheats>& cheats) const override
+    {
+        // Do nothing
+    }
+};