Allow to join an open group

Also:

* Refactor interacting with a remote event so that you can interact with
  a remote group as well
* Add a setting for group admins to pick between an open and invite-only
  group
* Fix new groups without posts/todos/resources/events/conversations URL
  set
* Repair local groups that haven't got their
  posts/todos/resources/events/conversations URL set
* Add a scheduled job to refresh remote groups every hour
* Add a user setting to pick when to receive notifications when there's
  new members to approve (will be used when this feature is available)
* Fix pagination for members

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/mobilizon/users/setting.ex

@@ -13,6 +13,7 @@ defmodule Mobilizon.Users.Setting do
           notification_each_week: boolean,
           notification_before_event: boolean,
           notification_pending_participation: NotificationPendingNotificationDelay.t(),
+          notification_pending_membership: NotificationPendingNotificationDelay.t(),
           user: User.t()
         }
 
@@ -23,7 +24,8 @@ defmodule Mobilizon.Users.Setting do
     :notification_on_day,
     :notification_each_week,
     :notification_before_event,
-    :notification_pending_participation
+    :notification_pending_participation,
+    :notification_pending_membership
   ]
 
   @attrs @required_attrs ++ @optional_attrs
@@ -39,6 +41,10 @@ defmodule Mobilizon.Users.Setting do
       default: :one_day
     )
 
+    field(:notification_pending_membership, NotificationPendingNotificationDelay,
+      default: :one_day
+    )
+
     belongs_to(:user, User, primary_key: true, type: :id, foreign_key: :id, define_field: false)
 
     timestamps()