Zabbix

.......PS. [ZBXNEXT-9994] improved Zabbix Proxy throttling logics when history cache is pressured

Merge in ZBX/zabbix from feature/ZBXNEXT-9994-7.5-1 to master

* commit '79e81efa0885043578da912402186baa25bf8e83': (21 commits)
  .......PS. [ZBXNEXT-9994] fixed comment
  .......... [ZBXNEXT-9994] added changelog
  .......... [ZBXNEXT-9994] added changelog
  .......PS. [ZBXNEXT-9994] fixed warnings
  ........S. [ZBXNEXT-9994] fixed history cache heavy usage timer, fixed lockup on nested lock and moved out the statistic logging to separate function
  .......PS. [ZBXNEXT-9994] fixed timer logics
  ........S. [ZBXNEXT-9994] added coding style fix
  .......... [ZBXNEXT-9994] removed debug logs
  .......PS. [ZBXNEXT-9994] various fixes
  .......PS. [ZBXNEXT-9994] fixed log message
  .......PS. [ZBXNEXT-9994] fixed warnings
  .......PS. [ZBXNEXT-9994] added warning under supression
  .......PS. [ZBXNEXT-9994] fixed
  .......PS. [ZBXNEXT-9994] send more flag on active px if upload is disabled
  .......PS. [ZBXNEXT-9994] renamed
  .......PS. [ZBXNEXT-9994] reimplemented
  .......PS. [ZBXNEXT-9994] restored old logics
  .......PS. [ZBXNEXT-9994] large_history_data -> pending_history
  .......PS. [ZBXNEXT-9994] fixed header
  .......PS. [ZBXNEXT-9994] fixed style
  ...