Bug 15129: Add Koha::Object for issuing rules and let smart-rules.pl use it

Bug 15129: Add Koha::Object for issuing rules and let smart-rules.pl use it

Test plan:
1. Make sure that in koha/admin/smart-rules.pl you can still create
   new rules and that the new rules have all their values remained
   after saving the rule (so put to every field something).
2. Make sure you can edit that rule
3. Make sure you can delete that rule

Sponsored-by: Vaara-kirjastot
Followed test plan, works as expected
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com