Gherkin java codegen

[aslakhellesoy]

Summary

Generate GherkinDialects.java at build time, using Groovy as a template engine and the root gherkin-languages.json as data for the template. This fixes #1957.

Details

With this change the library no longer needs to parse JSON at runtime. This makes the library:

• more performant (not really important)
• smaller memory footprint (not really important)
• more secure and less maintenance needed, because 3rd party JSON parsers tend to have CVEs

With this change there is no need to copy the gherkin-languages.json file either.

Motivation and Context

See #1957

Types of changes

• Breaking change.

Checklist:

• The change has been ported to Java.
• The change has been ported to Ruby.
• The change has been ported to JavaScript.
• The change has been ported to Go.
• The change has been ported to .NET.
• I've added tests for my code.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have updated the CHANGELOG accordingly.

[aslakhellesoy]

Thanks for the feedback @mpkorstanje - fixed now I think. Good to merge?

[mpkorstanje]

LGTM. The one nit pick aside.

[mpkorstanje]

Cheers btw.

[ciaranmcnulty]

Looks good 👍