Implement unambiguous keywords

[mattwynne]

As described in https://github.com/cucumber/common/issues/768

[otrava7]

Godog doesn't currently have separate functions for different step types, we just use the Step function which takes a regex and a function. What are peoples thoughts on introducing functions for the different keywords as a first step? Having those functions would make it possible to record the keyword type so that we may assert it when matching in order to resolve the issue detailed above. Also, since these functions didn't exist before, we can implement unambiguous keywords from the get go, and it wouldn't be a breaking change.

[otrava7]

I got started on creating keyword functions and capturing the keywords. Will submit a PR once I've added the logic for enabling unambiguous keywords: https://github.com/cucumber/godog/compare/main...otrava7:godog:implement-unambiguous-keywords