Zabbix

A.F.....S. [ZBXNEXT-9138] fixed Zabbix server to work with recent versions of mysql_aurora

* commit 'cbfbdd0c197d1ca87af1244dc49e3003d0373dbc':
  ........S. [ZBXNEXT-9138] fixed ui db
  A......... [ZBXNEXT-9138] replaced "array_search" function with a more suitable "in_array" in several places; removed useless "message_format" parameter in the integration test
  ........S. [ZBXNEXT-9138] removed empty line
  ....I..... [ZBXNEXT-9138] fixed upgrade patch
  ........S. [ZBXNEXT-9138] small style fixes
  ........S. [ZBXNEXT-9138] renamed missed variables content_type to message_format
  .D........ [ZBXNEXT-9138] updated ChangeLog entry
  ..F....... [ZBXNEXT-9138] modified the import/export functionality to work with the new field instead of deprecated one
  ..F....... [ZBXNEXT-9138] modified the frontend code to work with the new field instead of deprecated one; removed unused views:
  A.F....... [ZBXNEXT-9138] renamed constants SMTP_MESSAGE_FORMAT_PLAIN_TEXT and SMTP_MESSAGE_FORMAT_HTML
  A.F....... [ZBXNEXT-9138] replaced "content_type" with "message_format" in mediatype.create, mediatype.update and mediatype.delete methods
  ........S. [ZBXNEXT-9138] rename content_type to message_format
  ........S. [ZBXNEXT-9138] fixed Zabbix server to work with recent versions of mysql_aurora