Bug 23893: Use in /cities

Bug 23893: Use in /cities

This patch makes the cities controller use the new methods from
Koha::Object.

To test:
1. Apply this patch
2. Run:
  $ kshell
 k$ prove t/db_dependent/api/v1/cities.t
=> SUCCESS: Tests pass!
3. Sign off :-D

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Joy Nelson <joy@bywatersolutions.com>