feat: add `blas/base/caxpy`

[aman-095]

Description

What is the purpose of this pull request?

This RFC proposes to add a routine to scale values of input complex double-precision floating-point vector by another complex double-precision floating-point constant and add the result to another complex double-precision floating-point vector as defined in BLAS Level 1 routines. Specifically adding @stdlib/blas/base/caxpy is proposed.

Related Issues

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None.

Questions

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No.

Other

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No.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• [x] Read, understood, and followed the contributing guidelines.

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@stdlib-js/reviewers

[aman-095]

Hey, @kgryte While implementing the C / Fortran implementation for the caxpy routine, I realized that it also requires scabs1 routine. So, I am working on dcabs1 and scabs1 now to remove the blocker for caxpy and igamax. 

[kgryte]

@aman-095 Sounds good!

[kgryte]

@aman-095 Are you planning on adding the C/Fortran implementation to this PR or in a follow-up PR?

[kgryte]

@aman-095 Looks like in your refactoring commit, you removed the C/Fortran implementation. Was this intentional?

[aman-095]

Hey, @kgryte, I have applied changes here based on #2468.