Zabbix

A......... [ZBX-27448] fixed inability to delete host, user or template groups when accordingly hosts, users or templates belonging to them were previously deleted in parallel requests

* commit '937fd354f7d55e06b5e8db3300943426f582f7b0':
  A......... [ZBX-27448] added group-set cleanup before deleting template group
  A......... [ZBX-27448] added group-set cleanup before deleting host or user group

(cherry picked from commit 9b2e95198ef1b450469678aa6389b42fb8b3ee7b)

Resolved conflicts in:
-	ui/include/classes/api/services/CHostGroup.php
-	ui/include/classes/api/services/CTemplateGroup.php