Notification when a new custom post type is detected

[hedgefield]

Related to #8511, when a new public custom post type is created, we should throw a notification that you can show/hide this post type from search engines using our configuration wizard.

This notification can be a site-wide notification with the following copy:

We detected that you created the new post type [post-type-name]. By default, this post type will be visible to search engines. You can change search engine visibility in our configuration wizard.

And at the end is a dismiss / X button. Clicking the link or the dismiss button will remove the notification. I hope that's enough info, otherwise let me know if you need a quick mockup.