Update pagination components without numbered items according to Pajamas specifications

The following components implement pagination without support for numbered items:

Let's update those so that they use gl-pagination.

The engineering effort required for this was considered too great, and the gain too little. Instead, the missing slot documentation to GlPagination will be added; the unused graphql_pagination component will be removed, and the design_management/components/toolbar/pagination.vue component will be left alone.

/cc @andyvolpe

Implementation Plan

Edited by Mark Florian