Add limit to penalty variant of collections call

Add limit to penalty variant of collections call

Add a limit and sort order param to the API method
open-ils.collections.users_of_interest.warning_penalty.retrieve

When a limit is supplied, users are sorted by set_date (default
DESC, for most recently set). Supplying "ASC" as a param will sort
by oldest.

Signed-off-by: Jeff Godin <jgodin@tadl.org>