LibFileSystem: Move TempFile from LibCore to LibFileSystem

As suggested in commit de18485

Userland/Libraries/LibCore/TempFile.h

@@ -1,41 +0,0 @@
-/*
- * Copyright (c) 2020-2023, the SerenityOS developers.
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#pragma once
-
-#include <AK/Error.h>
-#include <AK/NonnullOwnPtr.h>
-#include <AK/String.h>
-
-namespace Core {
-
-class TempFile {
-
-public:
-    static ErrorOr<NonnullOwnPtr<TempFile>> create_temp_directory();
-    static ErrorOr<NonnullOwnPtr<TempFile>> create_temp_file();
-
-    ~TempFile();
-
-    String const& path() const { return m_path; }
-
-private:
-    enum class Type {
-        Directory,
-        File
-    };
-
-    TempFile(Type type, String path)
-        : m_type(type)
-        , m_path(move(path))
-    {
-    }
-
-    Type m_type;
-    String m_path;
-};
-
-}