Zabbix

.......PS. [ZBXNEXT-9326] made items become unsupported when there are no pollers

Merge in ZBX/zabbix from feature/ZBXNEXT-9326-7.1 to master

* commit 'aa782677abc437d4bb4d9fe2f0bfc1ef72b02701':
  .......PS. [ZBXNEXT-9326] replaced Pollers with pollers
  .......PS. [ZBXNEXT-9326] added minor style fixes
  .......PS. [ZBXNEXT-9326] fixed warning
  .......PS. [ZBXNEXT-9326] updated error message
  .......PS. [ZBXNEXT-9326] removed redundant check during syncer startup
  .......PS. [ZBXNEXT-9326] updated changelog
  .......PS. [ZBX-17278] refactored
  .......PS. [ZBX-17278] made items with other types to have the same behaviour
  .......PS. [ZBX-17278] replaced redundant heap allocation for error with constant string
  .......PS. [ZBX-17278] made IPMI items unsupported when there are no IPMI pollers