Issue #1898474 by mondrake, Cottser, azinoman: pager.inc - Convert theme_ functions to Twig.

core/includes/pager.inc

core/includes/theme.inc

core/modules/search/search.pages.inc

core/modules/system/css/system.theme.css

core/modules/system/templates/pager.html.twig

...odules/views/lib/Drupal/views/Plugin/views/pager/Full.php

...odules/views/lib/Drupal/views/Plugin/views/pager/Mini.php

core/modules/views/views.theme.inc