Zabbix

.......... [DEV-1981] added new prometheus cases for calculated item tests

Merge in ZBX/zabbix from feature/DEV-1981-5.5 to master

* commit 'a9cd3a5b7661acc301dcd2a99c3c760dcaff4565':
  .......... [DEV-1981] fixed quotes
  .......... [DEV-1981] added new cases, removed double quotes
  .......... [DEV-1981] fixed double quotes and message check in trigger test
  .......... [DEV-1981] added rate() for trigger expressions
  .......... [DEV-1981] New Prometheus cases