message: [vcpkg-export-ifw] Some improvements
  Improvements:
  fix typos;
  remove outdated repository directory.
diff: @@ -35,7 +35,7 @@ namespace vcpkg::Commands::Export::IFW
  fs::path get_repository_dir_path(const std::string &export_id, const Options &ifw_options, const VcpkgPaths& paths)
  {
  - return ifw_options.maybe_packages_dir_path.has_value() ?
  + return ifw_options.maybe_repository_dir_path.has_value() ?
  fs::path(ifw_options.maybe_repository_dir_path.value_or_exit(VCPKG_LINE_INFO))
  : paths.root / (export_id + "-ifw-repository");
  }
  @@ -49,7 +49,7 @@ namespace vcpkg::Commands::Export::IFW
  fs::path get_installer_file_path(const std::string &export_id, const Options &ifw_options, const VcpkgPaths& paths)
  {
  - return ifw_options.maybe_config_file_path.has_value() ?
  + return ifw_options.maybe_installer_file_path.has_value() ?
  fs::path(ifw_options.maybe_installer_file_path.value_or_exit(VCPKG_LINE_INFO))
  : paths.root / (export_id + "-ifw-installer.exe");
  }
  @@ -279,6 +279,15 @@ R"###(<?xml version="1.0"?>
  System::println("Generating repository %s...", repository_dir.generic_string());
  + std::error_code ec;
  + Files::Filesystem& fs = paths.get_filesystem();
  +
  + fs.remove_all(repository_dir, ec);
  + Checks::check_exit(VCPKG_LINE_INFO,
  + !ec,
  + "Could not remove outdated repository directory %s",
  + repository_dir.generic_string());
  +
  const std::wstring cmd_line =
  Strings::wformat(LR"("%s" --packages "%s" "%s" > nul)",
  repogen_exe.native(),
  