Zabbix

A.F.I..PS. [ZBXNEXT-6311] moved host availability from hosts to host interfaces

Merge in ZBX/zabbix from feature/ZBXNEXT-6311-5.3 to master

* commit '756203ff5b2c6d58cb56e635cd1b9e62b1b82a5f':
  .......PS. [ZBXNEXT-6311] move interface structure definition to active item state
  .......PS. [ZBXNEXT-6311] fixed style
  .......PS. [ZBXNEXT-6311] fixed uninitialized data