The mistake was made when flags were moved to the database. The `notify_moderators` (something else) flag should be the last position on the list.
This commit contains 3 changes:
- update fixtures order;
- remove position and enable from fixtures (they can be overridden by admin and we don't want seed to restore them);
- migration to fix data if the order was not changed by admin.
After flags were moved to the database, with each save they are changing available PostActionTypes. Therefore, flag specs should clear the state before and after each example not just before.
In addition, we need to clear `nil` counts for dynamically created flags from serializer.
