Add option to filter users that are using seats from the admin/users page

Proposal

This proposal is to request the addition of filter options to view a list of users that are using seats (essentially filtering out any bots/service accounts), or view only a list of bots / users that are not counted as using seats.

The attached screenshot provides an example of the request (red box outlines a filter option to show only those users who are using up a seat):

This is an extension of #6995 (closed).