Add account migration UI (#11846)

Fix #10736

- Change data export to be available for non-functional accounts
- Change non-functional accounts to include redirecting accounts

app/serializers/activitypub/move_serializer.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+class ActivityPub::MoveSerializer < ActivityPub::Serializer
+  attributes :id, :type, :target, :actor
+  attribute :virtual_object, key: :object
+
+  def id
+    [ActivityPub::TagManager.instance.uri_for(object.account), '#moves/', object.id].join
+  end
+
+  def type
+    'Move'
+  end
+
+  def target
+    ActivityPub::TagManager.instance.uri_for(object.target_account)
+  end
+
+  def virtual_object
+    ActivityPub::TagManager.instance.uri_for(object.account)
+  end
+
+  def actor
+    ActivityPub::TagManager.instance.uri_for(object.account)
+  end
+end