message: `vcpkg portsdiff` Make output format closer to the CHANGELOG formatting
diff: @@ -68,7 +68,7 @@ namespace vcpkg::Commands::PortsDiff
  for (const std::string& name : ports_to_print)
  {
  const VersionT& version = names_and_versions.at(name);
  - System::println("%-20s %-16s", name, version);
  + System::println(" - %-14s %-16s", name, version);
  }
  }
  @@ -147,14 +147,14 @@ namespace vcpkg::Commands::PortsDiff
  const std::vector<std::string>& added_ports = setp.only_left;
  if (!added_ports.empty())
  {
  - System::println("\nThe following %d ports were added:\n", added_ports.size());
  + System::println("\nThe following %d ports were added:", added_ports.size());
  do_print_name_and_version(added_ports, current_names_and_versions);
  }
  const std::vector<std::string>& removed_ports = setp.only_right;
  if (!removed_ports.empty())
  {
  - System::println("\nThe following %d ports were removed:\n", removed_ports.size());
  + System::println("\nThe following %d ports were removed:", removed_ports.size());
  do_print_name_and_version(removed_ports, previous_names_and_versions);
  }
  @@ -164,10 +164,10 @@ namespace vcpkg::Commands::PortsDiff
  if (!updated_ports.empty())
  {
  - System::println("\nThe following %d ports were updated:\n", updated_ports.size());
  + System::println("\nThe following %d ports were updated:", updated_ports.size());
  for (const UpdatedPort& p : updated_ports)
  {
  - System::println("%-20s %-16s", p.port, p.version_diff.to_string());
  + System::println(" - %-14s %-16s", p.port, p.version_diff.to_string());
  }
  }
  