* Allow plural localized strings to not specify every case

* Canonicalize locale string for gen_l10n.dart script

* Refresh stocks example to use canonicalized locale

* Sort locales and method/properties/getters alphabetically

* Refresh stocks example to show proper sorting

* Sort Localization generation output

- When creating locales that were assumed from existing locales, the
file that is used is non-deterministic. This adds a sort to the iterator
to ensure that the same existing locale is used to generate the assumed
locale
- When generating material, cupertino and date localizations, the generated getters were not sorted. This
introduces an alphabetic sort

* remove main.dart.snapshot

* Add check for placeholders being an empty map

* Remove unnecessary properties from en_ES.arb in the stocks example

* Use getter instead of methods in the stocks example

* Fixed "annotating types for function expression parameters" lint issue from generated localizations delegate code

* Use raw string for l10n description

* Stock app refresh

This adds support for the fn key on macOS. It adds it to the key mappings as a supplemental mapping that overwrites the one from the Chrome headers, since the chrome headers have a TODO, but no implementation of the key.

Also, ignore the fn key entirely on macOS. This is because On macOS laptop keyboards, the fn key is used to generate home/end and f1-f12, but it ALSO generates a separate down/up event for the fn key itself. Other platforms hide the fn key, and just produce the key that it is combined with, so to keep it possible to write cross platform code that looks at which keys are pressed, the fn key is ignored.

* Add pubspec.yaml comment

* Add --help flag

* Use l10n tool to generate stocks i18n files

* Rename *_en_EN.arb to *_en_US.arb

* Fix l10n script

*Starting with arb files in lib/l10n, the tool creates the following by default:
1. An AppLocalizations class containing:
- an `AppLocalizationsDelegate`
- a `supportedLocales` property that returns a list of all supported locales.
- a `localizationsDelegate` property that returns a list containing this delegate along with `GlobalMaterialLocalizations.delegate`, `GlobalCupertinoLocalizations.delegate`, and `GlobalWidgetsLocalizations.delegate`.
2. One Dart `message_<locale>.dart` file for each arb file, as well as a `messages_all.dart` file that performs the locale message lookup. The tool infers the locale of each arb file from the @@Locale property or the arb file's name.

This updates the keyboard maps to use updated HID codes for game controller buttons (from Chrome), and to encode that GLFW "super" keys are what we call "meta" keys (i.e. Windows key or Command key).

* WIP on web plugin registry

* WIP on registering plugins

* WIP on web plugin registration

* Only generate `package:flutter_web_plugins` imports if plugins are
defined

* Add parsing test

* Add documentation

* Fix analyzer warnings

* add license headers

* Add tests for package:flutter_web_plugins

* Run `flutter update-packages --force-upgrade`

* Fix analyzer errors

* Fix analyzer error in test

* Update copyright and remove flutter SDK constraints

* Enable tests since engine has rolled

* add flutter_web_plugins tests to bots

* Create an empty .packages file for WebFs test

This fixes a breakage in fuchsia where package_config version 1.1.0 is
required but flutter_tools is currently locked to 1.05.

update dependencies; add a Web smoke test

https://github.com/dart-lang/sdk/issues/36900

This adds support for game controller buttons. It adds some supplemental USB HID codes that aren't available from the Chromium source code, and maps those on Android to the game pad buttons that Android supports. Other platforms are not supported yet.