[cpp] Fix regenerating dialect.cpp, and do so

[musicinmybrain]

🤔 What's changed?

I therefore adjusted the template in dialect.cpp.jq to match the #include and namespace we already have in dialect.cpp, then re-generated dialect.cpp, which incidentally brought in a couple of new translations.

⚡️ What's your motivation?

While investigating #414 (comment), I found that the #include path and namespace had changed in dialect.cpp, but the dialect.cpp.jq from which it is generated had not been updated to match.

🏷️ What kind of change is this?

• 🐛 Bug fix (non-breaking change which fixes a defect)

♻️ Anything particular you want feedback on?

📋 Checklist:

• I agree to respect and uphold the Cucumber Community Code of Conduct
• I've changed the behaviour of the code
  • I have added/updated tests to cover my changes.
• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
• Users should know about my change
  • I have added an entry to the "Unreleased" section of the CHANGELOG, linking to this pull request.

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This text was originally generated from a template, then edited by hand. You can modify the template here.