Paginate CI variables to 20 items and add pages button
Currently, the Ci variables list is an infinite list of items. We fetch up to 1.5k variables in one query (ouch!) and then the user has to scroll through this blob to reach any of the action buttons at the bottom of the list.
What we want instead is to load the first 20 variables and add pages button. Since we can sort alphabetically, we want the API ability to sort variables so that if a user change pages, we keep going forward in the sorted order.