Sort parameters, add customization from l10n.yaml

[Filipssh-chili]

For generating the remote_fallback_localization.dart file

• Alphabetized the parameters to match app_localizations, because it was causing trouble in an internal project,
• Added l10n.yaml file parsing for:
  • output-localization-file, so we can use .g.dart and other filenames
  • use-named-parameters, for projects that use named parameters in their localization

...Ideally, we could replace the input/output args with matching the config from l10n.yaml