dart: Acceptance tests are not implemented

[mpkorstanje]

🤔 What's the problem you've observed?

The Gherkin Parser for Dart does not implement the acceptance tests (e.g. compare the make file to to the javascript implementation). This is a problem because:

As of May 2016 Gherkin is implemented in 8 languages. This number is likely to increase to a dozen within a year or two. Very few programmers are intimate with all those languages. Therefore, in order to make it as easy as possible to refactor, fix bugs, add features and release packages it is essential that all implementations have a similar structure.

CONTRIBUTING.md - consistency between implementations

✨ Do you have a proposal for making it better?

Either:

• Use Berp to generate the parser.
• Remove Dart.

📚 Any additional context?

The Parser for Dart is also not generated using Berp #29

[mpkorstanje]

Note: Dart does actually implement some acceptance tests by duplicating the test data:

https://github.com/cucumber/gherkin/tree/main/dart/test/assets/testdata

The parser implementation however does not retain the StepKeywordType and so we can not use the actual acceptance test data (see #34).