- Adds a field to QueryCriteria that determines whether the sort provided is the controller's default sort
- Set this field to true iff sort not in query params. Default it to false
- Override $sort if a new default sort has been set on search state, and the param is true.
- Add tests!
In the filterer refactor for ListPostsController, the filter key was changed to `author` for consistency with the AuthorFilterGambit used in discussions. This commit adds a deprecated `user` filter back in for a release to allow for a graceful transition