Patch functionality to allow Yoast to control if author pages should be indexed or not

[mchanDev]

Description

This PR aims to address the issue noted in #1059

Yoast has introduced functionality to allow control over the indexing of author pages.

This option is controlled with an option called noindex-author-wpseo

Steps to Test

On a setup with Yoast and CoAuthors Plus installed Set noindex-author-wpseo to true, by toggling Show author archives in search results to the off position Observe that author pages are included in the sitemap Checkout CoAuthors Plus to this branch Observe that author archive pages are not included in the sitemap

https://yoast.com/help/how-to-exclude-author-pages-from-sitemap/#customize