Zabbix

.......... [DEV-2531] added new common file for widgets

* commit 'e5828201955287879ccd62f426850f750e1c1309':
  .......... [DEV-2531] added comment in testFormGraphs autotest
  .......... [DEV-2531] added missing data source
  .......... [DEV-2531] added method which checks available item types on clock widget autotest
  .......... [DEV-2531] added method which checks available item types on graph widget autotests
  .......... [DEV-2531] added method which checks available items on autotest
  .......... [DEV-2531] added new common file for widgets
  .......... [DEV-2531] added method which checks possible item types in graph widget