Add widget support to SourceColumn

Allow passing a widget class to SourceColumn. This makes
using lambdas to render model column unnecesary and are
mostly removed too.

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/permissions/apps.py

@@ -11,6 +11,7 @@ from mayan.apps.common import (
     menu_secondary, menu_setup
 )
 from mayan.apps.common.signals import perform_upgrade
+from mayan.apps.navigation import SourceColumn
 
 from .handlers import handler_purge_permissions
 from .links import (
@@ -48,6 +49,8 @@ class PermissionsApp(MayanAppConfig):
             )
         )
 
+        SourceColumn(attribute='label', is_identifier=True, source=Role)
+
         menu_list_facet.bind_links(
             links=(
                 link_acl_list, link_role_groups, link_role_permissions,