[RFC]: add C implementation for `@stdlib/math/base/special/gamma-lanczos-sum-expg-scaled`

[gunjjoshi]

Description

This RFC proposes adding C implementation for @stdlib/math/base/special/gamma-lanczos-sum-expg-scaled.

Related Issues

Related issues #649.

Questions

No.

Other

No.

Checklist

• I have read and understood the Code of Conduct.
• Searched for existing issues and pull requests.
• The issue name begins with RFC:.

[gunjjoshi]

I would like to work on this one.