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>

js/src/components/Participation/ConfirmParticipation.vue

@@ -38,8 +38,9 @@
 <script lang="ts">
 import { Component, Prop, Vue } from "vue-property-decorator";
 import { confirmLocalAnonymousParticipation } from "@/services/AnonymousParticipationStorage";
+import { IParticipant } from "../../types/participant.model";
 import RouteName from "../../router/name";
-import { EventJoinOptions, IParticipant } from "../../types/event.model";
+import { EventJoinOptions } from "../../types/event.model";
 import { CONFIRM_PARTICIPATION } from "../../graphql/event";
 
 @Component