Update CONTRIBUTORS from commit history

[ghost]

Update CONTRIBUTORS from commit history, add .mailmap to fix early mis-attributed contributions

Checklist

• Checked that there aren't other open pull requests for the same change.
• Added tests for any changes that have a runtime impact.
• Checked that all tests and type checking passes.
• For changes that have a potential impact on users of this project:
  • Updated relevant documentation to avoid inaccuracies.
  • Considered adding additional documentation.
  • Considered adding an example in ./examples for new features.
  • Considered updating our changelog (CHANGELOG.md).
• Considered granting push permissions to the PR branch,
  so maintainers can fix minor issues and keep your PR up to date.

[coveralls]

Coverage: 90.794%. Remained the same when pulling 8ceb557 on gjhiggins:update-contrib into cfe6e37 on RDFLib:main.

[aucampia]

LGTM, must have been some effort, but I think it is very valuable to have an accurate list and mailmap.

[aucampia]

I will merge tomorrow.