Zabbix

A.......S. [ZBXNEXT-9233] added LLD optimizations to perform discovery of 2m items/triggers/graphs within reasonable time limits, removed 30k dependent item limit

Merge in ZBX/zabbix from feature/ZBXNEXT-9233-7.1 to master

* commit '5036f8f69d73830203f700cc36e608c75b8e7cf9': (63 commits)
  .......... [ZBXNEXT-9233] removed tests discoveryrule copy tests that were incorrectly added by merge
  .D........ [ZBXNEXT-9233] update changelog entry
  ........S. [ZBXNEXT-9233] fixed warning
  .......... [ZBXNEXT-9233] fixed syntax error in testDependentItems.php
  ........S. [ZBXNEXT-9233] fixed warnings
  ........S. [ZBXNEXT-9233] fixed resetting discovered flag setting to dependent items when master item becomes not-discovered
  .......... [ZBXNEXT-9233] fixed prepare method for item prototype in dependent item API tests
  .......... [ZBXNEXT-9233,DEV-3971] adjusted dependent item API test
  .......... [ZBXNEXT-9233] added check for many LLD rules in dependent item depth and count API tests
  .......... [ZBXNEXT-9233] fixed error in dependent item depth and count API tests
  .......... [ZBXNEXT-9233] fixed error in dependent item depth and count API tests
  .......... [ZBXNEXT-9233] fixed error in dependent item depth and count API tests
  .......... [ZBXNEXT-9233] added dependent item depth and count API tests
  .......... [ZBXNEXT-9233] removed no longer used method in API test framework
  .......PS. [ZBXNEXT-9233] improved performance for initial configuration sync
  .......PS. [ZBXNEXT-9233] improved performance for initial configuration sync
  .......PS. [ZBXNEXT-9233] simplified item removal from host.items
  .......PS. [ZBXNEXT-9233] optimized master-dep item link caching
  .......PS. [ZBXNEXT-9233] optimized items removal not to inefficiently join items and item_discovery
  .......PS. [ZBXNEXT-9233] optimized item caching on host in configuration cache
  ...