Incomplete code coverage in `blas/base/dznrm2` and `blas/base/scnrm2`

[kgryte]

For context, see the coverage report posted to fcc9603#commitcomment-143981597.

Current unit tests for both blas/base/dznrm2 and blas/base/scnrm2 fail to cover all branches, resulting in less than 100% code coverage. It would be good if we could add more test cases to those packages to ensure full coverage.

[kgryte]

See @stdlib/lapack/base/dlassq for some ideas.

[gururaj1512]

Working on it..!

[gururaj1512]

@kgryte, Is there any to check coverage report before commiting and pushing?

[kgryte]

@gururaj1512 See the development guide: https://github.com/stdlib-js/stdlib/blob/4b0d2abf2706178f83da028fc39fe0fdc3d2c073/docs/development.md#testing