FileSys: rename SaveDataCheck archive to NCCH archive

According to the observation from game and 3dbrew "Used for accessing general NCCH data"

src/core/file_sys/archive_ncch.cpp

@@ -0,0 +1,62 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <memory>
+#include <vector>
+#include "common/common_types.h"
+#include "common/file_util.h"
+#include "common/logging/log.h"
+#include "common/string_util.h"
+#include "core/file_sys/archive_ncch.h"
+#include "core/file_sys/ivfc_archive.h"
+#include "core/hle/service/fs/archive.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// FileSys namespace
+
+namespace FileSys {
+
+static std::string GetNCCHContainerPath(const std::string& nand_directory) {
+    return Common::StringFromFormat("%s%s/title/", nand_directory.c_str(), SYSTEM_ID.c_str());
+}
+
+static std::string GetNCCHPath(const std::string& mount_point, u32 high, u32 low) {
+    return Common::StringFromFormat("%s%08x/%08x/content/00000000.app.romfs", mount_point.c_str(),
+                                    high, low);
+}
+
+ArchiveFactory_NCCH::ArchiveFactory_NCCH(const std::string& nand_directory)
+    : mount_point(GetNCCHContainerPath(nand_directory)) {}
+
+ResultVal<std::unique_ptr<ArchiveBackend>> ArchiveFactory_NCCH::Open(const Path& path) {
+    auto vec = path.AsBinary();
+    const u32* data = reinterpret_cast<u32*>(vec.data());
+    std::string file_path = GetNCCHPath(mount_point, data[1], data[0]);
+    auto file = std::make_shared<FileUtil::IOFile>(file_path, "rb");
+
+    if (!file->IsOpen()) {
+        return ResultCode(-1); // TODO(Subv): Find the right error code
+    }
+    auto size = file->GetSize();
+
+    auto archive = std::make_unique<IVFCArchive>(file, 0, size);
+    return MakeResult<std::unique_ptr<ArchiveBackend>>(std::move(archive));
+}
+
+ResultCode ArchiveFactory_NCCH::Format(const Path& path,
+                                       const FileSys::ArchiveFormatInfo& format_info) {
+    LOG_ERROR(Service_FS, "Attempted to format a NCCH archive.");
+    // TODO: Verify error code
+    return ResultCode(ErrorDescription::NotAuthorized, ErrorModule::FS, ErrorSummary::NotSupported,
+                      ErrorLevel::Permanent);
+}
+
+ResultVal<ArchiveFormatInfo> ArchiveFactory_NCCH::GetFormatInfo(const Path& path) const {
+    // TODO(Subv): Implement
+    LOG_ERROR(Service_FS, "Unimplemented GetFormatInfo archive %s", GetName().c_str());
+    return ResultCode(-1);
+}
+
+} // namespace FileSys