Change last_status_at to be a date, not datetime (#12966)

* Return last_status_at as date, not datetime

* Fix relative timestamp for dates when delay is inferior to 1 day

* Also fix public directory

* Fix error when last_status_at isn't set

app/serializers/rest/account_serializer.rb

@@ -55,4 +55,8 @@ class REST::AccountSerializer < ActiveModel::Serializer
   def moved_and_not_nested?
     object.moved? && object.moved_to_account.moved_to_account_id.nil?
   end
+
+  def last_status_at
+    object.last_status_at&.to_date&.iso8601
+  end
 end