Add support to auto-updates in the Pro version

[andergmartins]

Links to use as reference:

https://make.wordpress.org/core/2020/07/30/recommended-usage-of-the-updates-api-to-support-the-auto-updates-ui-for-plugins-and-themes-in-wordpress-5-5/

https://wordpress.org/support/article/configuring-automatic-background-updates/

https://rudrastyh.com/wordpress/self-hosted-plugin-update.html

https://kinsta.com/blog/wordpress-automatic-updates/

https://github.com/YahnisElsts/wp-update-server