Fixed PHPDoc: return annotation
EZP-20530: remove incomplete tests (already tested in integration and mock)
EZP-20530: Extract common service methods into a separate class
EZP-20530: put new DomainMapper into use
Fixed argument mutation
Fixed PHPDoc: params
EZP-20530: implement missing unit tests for SearchService
EZP-20530: mark invalid validator tests as skipped instead of incomplete