flutter-tool: enum cleanup

[kevmoo]

Made BuildMode an enum. Inlined a number of helpers
Inlined associated helpers into FlutterProjectType, ServiceWorkerStrategy, and Browser enums
Updated associated CLI code to use helpers

Removed very outdated enum helpers

Migrated a few places to use switch expressions
Migrated one type to abstract final with only static members

Updated buildWeb command to take ServiceWorkerStrategy over String
(nice to have this type-safe)

Introduced CliEnum interface for all related types.

[kevmoo]

grumble grumble PTAL @christopherfujino grumble grumble

[christopherfujino]

LGTM

[auto-submit]

auto label is removed for flutter/flutter, pr: 124760, due to - The status or check suite Windows build_tests_2_3 has failed. Please fix the issues identified (or deflake) before re-applying this label.

[ditman]

👍 restarting the windows test, looks like a flake?

[ditman]

I wouldn't use the arrow here, what comes after it is ~80 lines long

• https://dart.dev/tools/linter-rules#prefer_expression_function_bodies

[kevmoo]

where?

[ditman]

@kevmoo in the getDesiredCapabilities function body:

@visibleForTesting
Map<String, dynamic> getDesiredCapabilities(
  Browser browser,
  bool? headless, {
  List<String> webBrowserFlags = const <String>[],
  String? chromeBinary,
}) {
  return switch(...) {
  }
}