ISTWCMS-5509: adding pager template for pagination

templates/navigation/pager.html.twig

+{#
+/**
+ * @file
+ * Theme override for a pager.
+ *
+ * Available variables:
+ * - modifier_class: Variant classes to modify component.
+ * - heading: Accessible heading.
+ * - items: List of pager items.
+ *
+ */
+#}
+
+{% if items %}
+  {% include '@components/pager/pager.twig' with {
+    'modifier': '',
+    'heading': 'Pagination'|t,
+    'items': items,
+    'current': current
+  } only %}
+{% endif %}