FEATURE - Moderators can create and manage groups (#10432)

Enabling the moderators_manage_categories_and_groups site setting will allow moderator users to create/manage groups.

* show New Group form to moderators

* Allow moderators to update groups and read logs, where appropriate

* Rename site setting from create -> manage

* improved tests

* Migration should rename old log entries

* Log group changes, even if those changes mean you can no longer see the group

* Slight reshuffle

* RouteTo /g if they no longer have permissions to view group

config/site_settings.yml

@@ -1452,7 +1452,7 @@ security:
     regex: "^(Lax|Strict|Disabled|None)$"
   enable_escaped_fragments: true
   allow_index_in_robots_txt: true
-  moderators_create_categories: false
+  moderators_manage_categories_and_groups: false
   moderators_view_emails:
     client: true
     default: false