[analyzer] Missing completion for enum constants

[incendial]

Hi,

enum Test {
  first,
  last;

  static List<Test> get all => [fi /* continue typing here */];
}

enum values are not suggested inside the list literal, though both first and last (without the enum prefix) are valid.

[dart-github-bot]

Summary: The Dart analyzer is not suggesting enum constants as completions within a list literal, even though they are valid without the enum prefix. This prevents users from easily completing code with enum values.