[Delivers #43559337 #43559173] add source, rules and auth id to the agent listing

Resolves the bug 43559173 by adding pagination/filters to the agent listing.

I've added a new search_helper which provides a mechanism for adding columns to a listing e.g.
<%
add_column(I18n.t("agent_name.authority_id"), proc {|record| record['authority_id']}, :sortable => true, :sort_by => "authority_id")
%>
so any record template can add fields related to their type.