Add mutex section to diaginfo

When analyzing strace logs mapping futex calls to zabbix cache (on other) locking is not trivial. To make it easier a new diaginfo section must be added to dump addresses of Zabbix mutexes. While it would not be exact match of the futex call parameters, it would be easy to map zabbix locks to futex call parameters. The mutex section format will be:

{
  "locks": [
    {
      "ZBX_MUTEX_LOG": "0x123456780"
    },
    {
      "ZBX_MUTEX_CACHE": "0x123456781"
    },
    {
      "ZBX_MUTEX_TRENDS": "0x123456782"
    },
    {
      "ZBX_MUTEX_MODBUS": "0x123456783"
    },
    {
      "ZBX_RWLOCK_CONFIG": "0x123456790"
    }
  ]
}