.NET implementation of Cucumber Expressions

[gasparnagy]

Description

This is a port of the java implementaition to .NET / C# with the following differences:

• The ParameterTypeRegistry is not implemented here, only defines the IParameterTypeRegistry and IParameterType interfaces
• The matching logic is not implemented in the expression implementation (cucumber, regex). Currently this logic sits in SpecFlow and it is not that easy (or makes sense) to move it out.

Also added a test-dotnet GitHub action.

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• I have added tests to cover my changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added an entry to the "Unreleased" section of the CHANGELOG, linking to this pull request.

[gasparnagy]

I think the failing JavaScript tests are unrelated to this...

[aurelien-reeves]

I think the failing JavaScript tests are unrelated to this...

I do not reproduce the error on main, but I can reproduce it on your branch. Could you merge origin main into your branch?

Edit: indeed, after merging main in dotnet, tests are passing. Do you want I push the merge?

Edit 2: nevermind, I've been able to add the "Update branch" button to PRs