Zabbix

.......PS. [DEV-3755] removed C pointer storage in custom javascript object property

Merge in ZBX/zabbix from feature/DEV-3755-6.0 to release/6.0

* commit 'd1b0a7ec47f9d9dcc6acd7c5d62c1eda90f5a62c':
  .......... [DEV-3755] added js security tests
  .......PS. [DEV-3755] fixed memory leak when destroying js environment with global variables linked to C structures
  .......PS. [DEV-3755] removed automatic this object pushing to stack when attaching native data to js object
  .......PS. [DEV-3755] removed debug logging
  .......PS. [DEV-3755] replaced js object mapping by hardcoded property with mapping by object heap pointer
  .......PS. [DEV-3755] fixed memory leak when embedded native object retrieval failed in method accepting parameters
  .......PS. [DEV-3755] removed direct pointer access in custom javascript objects, added instanceof checks when accessing embedded C pointers from custom js objects