Give generic IndexView a usable default listing

Comment out `template_name = 'wagtailsites/index.html'` in wagtail.sites.views to see it in action. This consists of a single 'Name' column consisting of the str() representation of the object, linking to the URL obtained from edit_url_name.

wagtail/admin/templates/wagtailadmin/generic/index.html

@@ -1,5 +1,5 @@
 {% extends "wagtailadmin/base.html" %}
-{% load i18n %}
+{% load i18n wagtailadmin_tags %}
 
 {% block titletag %}{{ page_title }} {{ page_subtitle }}{% endblock %}
 
@@ -12,5 +12,8 @@
     {% endif %}
 
     {% block listing %}
+        <div class="nice-padding">
+            {% component table %}
+        </div>
     {% endblock %}
 {% endblock %}

wagtail/admin/views/generic/models.py

@@ -8,6 +8,7 @@ from django.views.generic.edit import BaseCreateView, BaseDeleteView, BaseUpdate
 from django.views.generic.list import BaseListView
 
 from wagtail.admin import messages
+from wagtail.admin.ui.tables import Table, TitleColumn
 from wagtail.core.log_actions import log
 
 from .base import WagtailAdminTemplateMixin
@@ -19,15 +20,25 @@ class IndexView(PermissionCheckedMixin, WagtailAdminTemplateMixin, BaseListView)
     index_url_name = None
     add_url_name = None
     edit_url_name = None
+    template_name = 'wagtailadmin/generic/index.html'
     context_object_name = None
     any_permission_required = ['add', 'change', 'delete']
 
+    def get_columns(self):
+        try:
+            return self.columns
+        except AttributeError:
+            return [
+                TitleColumn('name', accessor=str, url_name=self.edit_url_name),
+            ]
+
     def get_context_data(self, **kwargs):
         context = super().get_context_data(**kwargs)
         context['can_add'] = (
             self.permission_policy is None
             or self.permission_policy.user_has_permission(self.request.user, 'add')
         )
+        context['table'] = Table(self.get_columns(), context['object_list'])
         return context