Zabbix

.......... [DEV-3686] implemented proxy group related check in existing selenium tests and created new tests for proxy group form and list views

* commit '2603caf58c18abf032384228a83e385638581144':
  .......... [DEV-3686] removed TODO action after issue with table stats for proxy groups was fixed
  .......... [DEV-3686] fixed multiple minor coding style issues according to review comments
  .......... [DEV-3686] fixed checking proxies field and renaimed proxy that was cousing sorting issues
  .......... [DEV-3686] added proxy group checks to existing selenium tests and added new tests for proxy group list and form views