Federate pinned statuses over ActivityPub (#6610)

* Federate pinned statuses over ActivityPub

* Display pinned toots in web UI

Fix #6117

* Fix migration

* Fix tests

* Update outbox_serializer.rb

* Update remove_serializer.rb

* Update add_serializer.rb

* Update fetch_featured_collection_service.rb

app/controllers/api/v1/statuses/pins_controller.rb

@@ -11,12 +11,18 @@ class Api::V1::Statuses::PinsController < Api::BaseController
 
   def create
     StatusPin.create!(account: current_account, status: @status)
+    distribute_add_activity!
     render json: @status, serializer: REST::StatusSerializer
   end
 
   def destroy
     pin = StatusPin.find_by(account: current_account, status: @status)
-    pin&.destroy!
+
+    if pin
+      pin.destroy!
+      distribute_remove_activity!
+    end
+
     render json: @status, serializer: REST::StatusSerializer
   end
 
@@ -25,4 +31,24 @@ class Api::V1::Statuses::PinsController < Api::BaseController
   def set_status
     @status = Status.find(params[:status_id])
   end
+
+  def distribute_add_activity!
+    json = ActiveModelSerializers::SerializableResource.new(
+      @status,
+      serializer: ActivityPub::AddSerializer,
+      adapter: ActivityPub::Adapter
+    ).as_json
+
+    ActivityPub::RawDistributionWorker.perform_async(Oj.dump(json), current_account)
+  end
+
+  def distribute_remove_activity!
+    json = ActiveModelSerializers::SerializableResource.new(
+      @status,
+      serializer: ActivityPub::RemoveSerializer,
+      adapter: ActivityPub::Adapter
+    ).as_json
+
+    ActivityPub::RawDistributionWorker.perform_async(Oj.dump(json), current_account)
+  end
 end