Zabbix

.......... [DEV-2490] added new Selenium autotest for Maintenance page

* commit 'ed700b65b8ac1b763315f33e61fa6c11b64f7ab6':
  .......... [DEV-2490] added todo after zbx fix
  .......... [DEV-2490] added dataSource
  .......... [DEV-2490] fixed code and code formatting style
  .......... [DEV-2490] minor styling adjustments: removed quotation for timestamp(api), added extra spaces for function
  .......... [DEV-2490] created the separate folder for maintenance, updated related files
  .......... [DEV-2490] fixed the formatting, added delete all case
  .......... [DEV-2490] did minor styling adjustments, added filter element for checking the buttons
  .......... [DEV-2490] minor improvements after updating to master (used new methods)
  .......... [DEV-2490] updated the layout tests, added majoriry of requested changes
  .......... [DEV-2490] Changed the filter's label, minor data adjustment
  .......... [DEV-2490] added new tests for the Maintenance page

(cherry picked from commit 893e73a63a793f94fa22efc1d1cbd55b6668854e)