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/Group/GroupSection.vue

@@ -41,7 +41,7 @@ section {
 
   .create-slot {
     display: flex;
-    justify-content: end;
+    justify-content: flex-end;
     padding-bottom: 0.5rem;
     padding-right: 0.5rem;
   }

js/src/components/Group/JoinGroupWithAccount.vue

@@ -0,0 +1,30 @@
+<template>
+  <redirect-with-account
+    :uri="uri"
+    :pathAfterLogin="`/@${preferredUsername}`"
+    :sentence="sentence"
+  />
+</template>
+<script lang="ts">
+import { Component, Prop, Vue } from "vue-property-decorator";
+import RedirectWithAccount from "@/components/Utils/RedirectWithAccount.vue";
+import RouteName from "../../router/name";
+
+@Component({
+  components: { RedirectWithAccount },
+})
+export default class JoinGroupWithAccount extends Vue {
+  @Prop({ type: String, required: true }) preferredUsername!: string;
+
+  get uri(): string {
+    return `${window.location.origin}${
+      this.$router.resolve({
+        name: RouteName.GROUP,
+        params: { preferredUsername: this.preferredUsername },
+      }).href
+    }`;
+  }
+
+  sentence = this.$t("We will redirect you to your instance in order to interact with this group");
+}
+</script>