Zabbix

.......... [DEV-4695] extended maintenance form Selenium autotest scenarios

Merge in ZBX/zabbix from feature/DEV-4695-7.5 to master

* commit '62011b899917e0c2dce23d7d665f4d2a0e08ea1f':
  .......... [DEV-4695] fixed spelling
  .......... [DEV-4695] added missing test cases and fixed coding style issues in master based branch
  .......... [DEV-4695] made more changes after code review, fixed failing parts of tests
  .......... [DEV-4695] made the changes required in code review, cherry-picked commit d4ac3a2da34, resolved conflicts
  .......... [DEV-4695] removed unnecessary comma
  .......... [DEV-4695] made changes accordingly to problems found in syntax check build
  .......... [DEV-4695] edited expected periods table header text, added field with asterisk to list in periods form
  .......... [DEV-4695] fixed typo
  .......... [DEV-4695] adjusted test for inline validation
  .......... [DEV-4695] deleted accidentally added files during merge
  .......... [DEV-4695] changed a variable from form to dialog type in screenshot assertion
  .......... [DEV-4695] renamed period form method back to its previous name to check screenshot failure reason
  .......... [DEV-4695] moved period form screenshot assertion into the period type cycle
  .......... [DEV-4695] added period form checks, added more scenarios in existing methods
  .......... [DEV-4695] completed create and update scenarios
  .......... [DEV-4695] continued period layout test, began create methods new version
  .......... [DEV-4695] upgraded layout and cancel scenarios