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 'f96f23590898640065ffb9393f72f39088b3afdf': (46 commits)
  .......... [ZBXNEXT-6311] selenium: fixed inheritance test after branch update
  ..F....... [ZBXNEXT-6311,ZBXNEXT-6314] changes in host availability widget
  .......... [ZBXNEXT-6311] selenium: extracted constants and variable for better code readability
  .......... [ZBXNEXT-6311] selenium: changed way of creating test data
  .......... [ZBXNEXT-6311] selenium: added small fixes to test
  .......... [ZBXNEXT-6311] selenium: added test for availability popup check
  ..F....... [ZBXNEXT-6314] fixed method doc block; fail if empty array is passed
  .......... [ZBXNEXT-6311] selenium: fixed lld test after merge
  .......PS. [ZBXNEXT-6311] corrected DB schema
  .......... [ZBXNEXT-6311] fixed interfaces in items and db data in availabality widget in tests
  .......... [ZBXNEXT-6311] fixed selenium tests
  .......PS. [ZBXNEXT-6311] code review 2 rework
  .......... [ZBXNEXT-6311] fixed trigger inheritance test
  .......... [ZBXNEXT-6311] fixed administration and item tests
  .......... [ZBXNEXT-6311] fixed table selectors in tests
  .......... [ZBXNEXT-6311] fixed page hosts test
  ..F....... [ZBXNEXT-6314] fixed code style
  ..F....... [ZBXNEXT-6314] fixed a semicolon being displayed instead of interface for hosts without a single interface
  .......... [ZBXNEXT-6311] fixed test data
  .......PS. [ZBXNEXT-6311] fixed unnecessary assignment to NULL
  ...