Major project restructuring

Remove unecessary files and made the tree much more cleaner.

Signed-off-by: Ronald Caesar <github43132@proton.me>

core/common/Error.h

@@ -0,0 +1,20 @@
+// Copyright 2025 Xenon Emulator Project. All rights reserved.
+
+#pragma once
+
+#include <string>
+
+namespace Base
+{
+
+// Like GetLastErrorMsg(), but passing an explicit error code.
+// Defined in error.cpp.
+[[nodiscard]] std::string NativeErrorToString(const s32 e);
+
+// Generic function to get last error message.
+// Call directly after the command or use the error num.
+// This function might change the error code.
+// Defined in error.cpp.
+[[nodiscard]] std::string GetLastErrorMsg();
+
+}  // namespace Base