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/graphql/schema/search.ex

@@ -4,6 +4,8 @@ defmodule Mobilizon.GraphQL.Schema.SearchType do
   """
   use Absinthe.Schema.Notation
 
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Events.Event
   alias Mobilizon.GraphQL.Resolvers.Search
 
   @desc "Search persons result"
@@ -24,6 +26,21 @@ defmodule Mobilizon.GraphQL.Schema.SearchType do
     field(:elements, non_null(list_of(:event)), description: "Event elements")
   end
 
+  interface :interactable do
+    field(:url, :string, description: "A public URL for the entity")
+
+    resolve_type(fn
+      %Actor{type: :Group}, _ ->
+        :group
+
+      %Event{}, _ ->
+        :event
+
+      _, _ ->
+        nil
+    end)
+  end
+
   object :search_queries do
     @desc "Search persons"
     field :search_persons, :persons do
@@ -58,5 +75,12 @@ defmodule Mobilizon.GraphQL.Schema.SearchType do
 
       resolve(&Search.search_events/3)
     end
+
+    @desc "Interact with an URI"
+    field :interact, :interactable do
+      arg(:uri, non_null(:string), description: "The URI for to interact with")
+
+      resolve(&Search.interact/3)
+    end
   end
 end