Update the text in admin settings to use "toolbar" instead of "admin bar"

The text for the **Display relevant page stats in the Admin bar** setting found in the admin settings section should be updated.

This currently uses the term "admin bar" which is out of date and not the official terminology used by WordPress. See [here](https://wordpress.org/documentation/article/toolbar/) where it's referred to as the "toolbar".

WordPress changed the name from the "Admin Bar" to the "Toolbar" in WordPress 3.3, released in December 2011 so we should update this to be inline with the official WordPress name.