Zabbix

A.F....... [ZBX-25037] fixed slow performance due to show variables and tables queries

* commit '5de88c7b6e46c400654c39743af755d30b99c59d':
  .......... [ZBX-25037] added changelog
  A......... [ZBX-25037] added empty lines before and after function setCharset declaration
  A......... [ZBX-25037] replaced double quotes with single quotes, capitalized sql query, replaced warning with error
  A......... [ZBX-25037] removed redundant variable declaration
  A......... [ZBX-25037] removed redundant variable declaration, switched trigger_error() for setWarning(), added a translation string
  A......... [ZBX-25037] implemented post review code style fixes for MysqlDbBackend.php
  A......... [ZBX-25037] improved code quality and removed redundant code for dbversion check query speed fix
  ..F....... [ZBX-24972] fixed slow performance due to show variables and tables queries
  ..F....... [ZBX-24972] fixed slow performance due to show variables and tables queries

(cherry picked from commit c9f0608333ccb5be44ca9637c5b813eba2d796ec)