Zabbix

........S. [ZBX-22126] fixed trends being deleted from cache and retrieved from database when data older than 1 hour is received

Merge in ZBX/zabbix from feature/ZBX-22126-5.0 to release/5.0

* commit 'c7877a5e428de6053847a40cbadbb245680b3515':
  .D........ [ZBX-22126] added ChangeLog and small style fix
  ........S. [ZBX-22126] fixed trend sync when Zabbix server is being stopped
  ........S. [ZBX-22126] avoided locking trends if no items are deleted and improved lock usage
  ........S. [ZBX-22126] avoided locking trends if no items are deleted and improved lock usage
  ........S. [ZBX-22126] fixed minor coding style and formatting issues
  ........S. [ZBX-22126] avoid trend flush for trends without updates
  ........S. [ZBX-22126] added back periodic trend flushing
  ........S. [ZBX-22126] fixed trends being deleted from cache and retrieved from database when data older than 1 hour is received